Modus Themes (Modus Operandi and Modus Vivendi)

Accessible themes for GNU Emacs, conforming with the highest accessibility standard for colour contrast between background and foreground values (WCAG AAA)

This manual, written by Protesilaos Stavrou, describes the customisation options for the modus-operandi and modus-vivendi themes, and provides every other piece of information pertinent to them. The document corresponds to version 0.13.0, expected to be released in late September 2020. As such, the present entry should be considered a work-in-progress.

Copyright (C) 2020 Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts.

Info manual HTML version.

1 Overview

The Modus themes are designed for accessible readability. They conform with the highest standard for colour contrast between any given combination of background and foreground colours. This corresponds to the WCAG AAA standard, which specifies a minimum rate of distance in relative luminance of 7:1.

Modus Operandi (modus-operandi) is a light theme, while Modus Vivendi (modus-vivendi) is dark. Each theme’s colour palette is designed to meet the needs of the numerous interfaces that are possible in the Emacs computing environment.

The overarching objective of this project is to always offer accessible colour combinations. There shall never be a compromise on this principle. If there is an inescapable trade-off between readability and stylistic considerations, we will always opt for the former.

To ensure that users have a consistently accessible experience, the themes strive to achieve as close to full face coverage as possible (see Face coverage).

Starting with version 0.12.0, the themes are built into Emacs. Their version is that of the latest tagged release. This is because I (Protesilaos Stavrou) do not have push privileges to the Emacs repository and must contact the mailing list for someone else to make the changes for me. As you can understand, it would be too tedious to do this each time I make a commit.

If I am ever granted access to the Emacs git repo, I will make sure that the built-in themes are synced with the HEAD of my master branch.

1.1 How do the themes look like

Check the web page with the screen shots. There are lots of scenaria on display that draw attention to details and important aspects in the design of the themes. They also showcase the numerous customisation options.

Customisation options.

2 Installation

The Modus themes are built into Emacs’ development branch (master) which corresponds to the nominal version 28.0.50. Otherwise they can be installed using Emacs’ package manager or manually from their code repository.

Modus Operandi (light theme) and Modus Vivendi (dark) are normally distributed as standalone packages in Emacs-specific archives: GNU ELPA, MELPA, and MELPA Stable. There also exist packages for GNU/Linux distributions.

2.1 Install from the archives

modus-operandi-theme and modus-vivendi-theme are available from GNU Elpa, Melpa, Melpa-Stable.

Prior to querying any package archive, make sure to have updated the index, with M-x package-refresh-contents. Then all you need to do is type M-x package-install and specify the theme of your choice.

GNU Elpa and Melpa-Stable contain the last tagged release. While Melpa builds from the latest commit to the Modus theme’s Git repository.

2.2 Install on GNU/Linux

The themes are also available from the archives of some GNU/Linux distributions. These should correspond to a tagged release rather than building directly from the latest Git commit. It all depends on the distro’s packaging policies.

2.2.1 Debian 11 Bullseye

The two themes are distributed as a single package for Debian and its derivatives. Currently in the unstable and testing suites and should be available in time for Debian 11 Bullseye (next stable).

Get them with:

sudo apt install elpa-modus-themes

2.2.2 GNU Guix

Users of either the Guix System (the distro) or just Guix (the package manager) can get each theme as a standalone package.

guix package -i modus-operandi-theme

And/or:

guix package -i modus-vivendi-theme

3 Enable and load

This section documents techniques on how to load the theme of your choice and how to further control its initialisation. It also includes some sample code snippets that could help you in the task, especially if you intend to use both Modus Operandi and Modus Vivendi.

3.1 Load automatically

A simple way to load the theme from your Emacs initialisation file is to include either of the following expressions:

(load-theme 'modus-operandi t)          ; Light theme
(load-theme 'modus-vivendi t)           ; Dark theme

Make sure to remove any other theme that is being loaded, otherwise you might run into unexpected issues.

Note that you can always M-x disable-theme and specify an item. The command does exactly what its name suggests. To deactivate all enabled themes at once, in case you have multiple of them enabled, you may evaluate the expression (mapc #'disable-theme custom-enabled-themes).

3.2 Load at a given time or at sunset/sunrise

It is possible to schedule a time during the day at or after which a given theme will be loaded.1

;; Light for the day
(load-theme 'modus-operandi t t)
(run-at-time "05:00" (* 60 60 24)
             (lambda ()
               (enable-theme 'modus-operandi)))

;; Dark for the night
(load-theme 'modus-vivendi t t)
(run-at-time "21:00" (* 60 60 24)
             (lambda ()
               (enable-theme 'modus-vivendi)))

A modified version of the above technique is to use the sunrise and sunset as references, instead of specifying a fixed value.2 If you set calendar-latitude and calendar-longitude (defined in the built-in solar.el library—read it with M-x find-library), you can automatically switch between both themes at the appropriate time-of-day. Note that those calendar variables need to be set before loading the themes.

;; Define coordinates
(setq calendar-latitude 35.17
      calendar-longitude 33.36)

;; Light at sunrise
(load-theme 'modus-operandi t t)
(run-at-time (nth 1 (split-string (sunrise-sunset)))
             (* 60 60 24)
             (lambda ()
               (enable-theme 'modus-operandi)))

;; Dark at sunset
(load-theme 'modus-vivendi t t)
(run-at-time (nth 4 (split-string (sunrise-sunset)))
             (* 60 60 24)
             (lambda ()
               (enable-theme 'modus-vivendi)))

For the sake of completeness, the load-theme call in these snippets is slightly different than the one shown in Load automatically, because it does not enable the theme directly: the subsequent enable-theme does that when needed.

3.3 Toggle between the themes on demand

With both themes available, it is possible to design a simple command to switch between them on demand.

(defun modus-themes-toggle ()
  "Toggle between `modus-operandi' and `modus-vivendi' themes."
  (interactive)
  (if (eq (car custom-enabled-themes) 'modus-operandi)
      (progn
        (disable-theme 'modus-operandi)
        (load-theme 'modus-vivendi t))
    (disable-theme 'modus-vivendi)
    (load-theme 'modus-operandi t)))

3.4 Configure options prior to loading

If you plan to use both themes and wish to apply styles consistently (see Customisation Options), you could define wrapper functions around the standard load-theme command. These extend the simple function we presented in Toggle between the themes on demand.

Here is a comprehensive setup (the values assigned to the variables are just for the sake of this demonstration):3

(defmacro modus-themes-format-sexp (sexp &rest objects)
  `(eval (read (format ,(format "%S" sexp) ,@objects))))

(dolist (theme '("operandi" "vivendi"))
  (modus-themes-format-sexp
   (defun modus-%1$s-theme-load ()
     (setq modus-%1$s-theme-slanted-constructs t
           modus-%1$s-theme-bold-constructs t
           modus-%1$s-theme-fringes 'subtle ; {nil,'subtle,'intense}
           modus-%1$s-theme-mode-line '3d ; {nil,'3d,'moody}
           modus-%1$s-theme-faint-syntax nil
           modus-%1$s-theme-intense-hl-line nil
           modus-%1$s-theme-intense-paren-match nil
           modus-%1$s-theme-no-link-underline t
           modus-%1$s-theme-prompts nil ; {nil,'subtle,'intense}
           modus-%1$s-theme-completions 'moderate ; {nil,'moderate,'opinionated}
           modus-%1$s-theme-diffs nil ; {nil,'desaturated,'fg-only}
           modus-%1$s-theme-org-blocks 'greyscale ; {nil,'greyscale,'rainbow}
           modus-%1$s-theme-headings  ; Read further below in the manual for this one
           '((1 . line)
             (t . rainbow-line-no-bold))
           modus-%1$s-theme-variable-pitch-headings t
           modus-%1$s-theme-scale-headings t
           modus-%1$s-theme-scale-1 1.1
           modus-%1$s-theme-scale-2 1.15
           modus-%1$s-theme-scale-3 1.21
           modus-%1$s-theme-scale-4 1.27
           modus-%1$s-theme-scale-5 1.33)
     (load-theme 'modus-%1$s t))
   theme))

(defun modus-themes-toggle ()
  "Toggle between `modus-operandi' and `modus-vivendi' themes."
  (interactive)
  (if (eq (car custom-enabled-themes) 'modus-operandi)
      (progn
        (disable-theme 'modus-operandi)
        (modus-vivendi-theme-load))
    (disable-theme 'modus-vivendi)
    (modus-operandi-theme-load)))

4 Customisation Options

The Modus themes are highly configurable. Though they should work well without any further tweaks.

By default, all customisation options are set to nil.

All customisation options need to be evaluated before loading their theme (see Enable and load).

4.1 Option for more bold constructs

Symbol names:

  • modus-operandi-theme-bold-constructs
  • modus-vivendi-theme-bold-constructs

Possible values:

  1. nil (default)
  2. t

Display several constructs in bold weight. This concerns keywords and other important aspects of code syntax. It also affects certain mode line indicators.

The default is to only use a bold weight when it is necessary.

Additionally and while not necessary, to define the precise weight for bold constructs, you can change the typographic intensity of the bold face. Assuming your typeface of choice supports a “semibold” weight, adding the following snippet to your init file should suffice:

(set-face-attribute 'bold nil :weight 'semibold)

The standard is a bold weight. It requires no further intervention.

4.2 Option for more slanted constructs

Symbol names:

  • modus-operandi-theme-slanted-constructs
  • modus-vivendi-theme-slanted-constructs

Possible values:

  1. nil (default)
  2. t

Choose to render more faces in slanted text (italics). This typically affects documentation strings and code comments.

The default is to not use italics unless it is absolutely necessary.

4.3 Option for faint code syntax highlighting

Symbol names:

  • modus-operandi-theme-faint-syntax
  • modus-vivendi-theme-faint-syntax

Possible values:

  1. nil (default)
  2. t

Use less saturated colours in programming modes for highlighting code syntax. The default is to use saturated colours.

This option essentially affects the font-lock faces, so it may also have effects in other places that are hard-wired to rely directly on font-lock. The author is aware of vc-dir as a case in point.

4.4 Option for no font mixing

Symbol names:

  • modus-operandi-theme-no-mixed-fonts
  • modus-vivendi-theme-no-mixed-fonts

Possible values:

  1. nil (default)
  2. t

By default, the themes configure some spacing-sensitive faces, such as Org tables and code blocks, to always inherit from the fixed-pitch face. This is to ensure that those constructs remain monospaced when users opt for something like the built-in M-x variable-pitch-mode. Otherwise the layout would break.

The obvious downside with this theme design is that users need to explicitly configure the font family of fixed-pitch in order to apply their desired typeface (see Font configurations for Org (and others)). That may be something they do not want to do. Hence this option to disable any kind of technique for mixing fonts.

4.5 Option for no link underline

Symbol names:

  • modus-operandi-theme-no-link-underline
  • modus-vivendi-theme-no-link-underline

Possible values:

  1. nil (default)
  2. t

Remove the underline effect from links, symbolic links, and buttons. The default is to apply an underline.

4.6 Option for command prompt styles

Symbol names:

  • modus-operandi-theme-prompts
  • modus-vivendi-theme-prompts

Possible values:

  1. nil (default)
  2. subtle
  3. intense

The symbols “subtle” and “intense” will apply a combination of accented background and foreground to the minibuffer and other REPL prompts (like M-x shell and M-x eshell). The difference between the two is that the latter has a more pronounced/noticeable effect than the former.

The default is to not use any background for such prompts, while only relying on an accented foreground colour.

4.7 Option for mode line presentation

Symbol names:

  • modus-operandi-theme-mode-line
  • modus-vivendi-theme-mode-line

Possible values:

  1. nil (default)
  2. 3d
  3. moody

The default value (nil) produces a two-dimensional effect both for the active and inactive modelines. The differences between the two are limited to distinct shades of greyscale values, with the active being more intense than the inactive.

A 3d symbol will make the active modeline look like a three-dimensional rectangle. Inactive modelines remain 2D, though they are slightly toned down relative to the default. This aesthetic is the same as what you get when you run Emacs without any customisations (emacs -Q on the command line).

While moody removes all box effects from the modelines and applies underline and overline properties instead. It also tones down a bit the inactive modelines. This is meant to optimise things for use with the moody package (hereinafter referred to as “Moody”), though it can work fine even without it.

Note that Moody does not expose any faces that the themes could style directly. Instead it re-purposes existing ones to render its tabs and ribbons. As such, there may be cases where the contrast ratio falls below the 7:1 target that the themes conform with (WCAG AAA). To hedge against this, we configure a fallback foreground for the moody option, which will come into effect when the background of the modeline changes to something less accessible, such as Moody ribbons (read the doc string of set-face-attribute, specifically :distant-foreground). This fallback comes into effect when Emacs determines that the background and foreground of the given construct are too close to each other in terms of colour distance. In effect, users would need to experiment with the variable face-near-same-color-threshold to trigger the fallback colour. We find that a value of 45000 would suffice, contrary to the default 30000. Do not set the value too high, because that would have the adverse effect of always overriding the default colour (which has been carefully designed to be highly accessible).

4.8 Option for completion framework aesthetics

Symbol names:

  • modus-operandi-theme-completions
  • modus-vivendi-theme-completions

Possible values:

  1. nil (default)
  2. moderate
  3. opinionated

This is a special option that has different effects depending on the completion UI. The interfaces can be grouped in two categories, based on their default aesthetics: (i) those that only or mostly use foreground colours for their interaction model, and (ii) those that combine background and foreground values for some of their metaphors. The former category encompasses the built-in tools, namely, Icomplete and Ido, as well as third party packages like Orderless and Flx. The latter covers Helm, Ivy, Selectrum, and similar.

A value of nil will respect the metaphors of each completion framework.

The symbol moderate will apply a combination of background and foreground that is fairly subtle. For Icomplete and friends this constitutes a departure from their default aesthetics, however the difference is small. While Helm et al will appear slightly different than their original looks, as they are toned down a bit.

The symbol opinionated will apply colour combinations that refashion the completion UI. For the Icomplete camp this means that intense background and foreground combinations are used: in effect their looks emulate those of Ivy and co. in their original style. Whereas the other group of packages will revert to an even more nuanced aesthetic with some additional changes to the choice of hues.

To appreciate the scope of this customisation option, you should spend some time with every one of the nil (default), moderate, and opinionated possibilities.

4.9 Option for fringe visibility

Symbol names:

  • modus-operandi-theme-fringes
  • modus-vivendi-theme-fringes

Possible values:

  1. nil (default)
  2. subtle
  3. intense

The “subtle” symbol will apply a greyscale background that is visible, yet close enough to the main background colour. While the “intense” symbol will use a more noticeable greyscale background.

The default is to use the same colour as that of the main background, meaning that the fringes are not obvious though they still occupy the space given to them by fringe-mode.

4.10 Option for line highlighting (hl-line-mode)

Symbol names:

  • modus-operandi-theme-intense-hl-line
  • modus-vivendi-theme-intense-hl-line

Possible values:

  1. nil (default)
  2. t

Draw the current line of hl-line-mode or its global equivalent in a more prominent background colour. This would also affect several packages that enable hl-line-mode, such as elfeed and mu4e.

The default is to use a more subtle grey.

4.11 Option for parenthesis matching (show-paren-mode)

Symbol names:

  • modus-operandi-theme-intense-paren-match
  • modus-vivendi-theme-intense-paren-match

Possible values:

  1. nil (default)
  2. t

Apply a more intense background to the matching parentheses (or delimiters). This affects tools such as the built-in show-paren-mode. The default is to use a subtle warm colour for the background of those overlays.

4.12 Option for diff buffer looks

Symbol names:

  • modus-operandi-theme-diffs
  • modus-vivendi-theme-diffs

Possible values:

  1. nil (default)
  2. desaturated
  3. fg-only

By default the themes will apply richly coloured backgrounds to the output of diffs, such as those of diff-mode, ediff, smerge-mode, and magit. These are colour combinations of an accented background and foreground so that, for example, added lines have a pronounced green background with an appropriate shade of green for the affected text. Word-wise or “refined” changes follow this pattern but use different shades of those colours to remain distinct.

A desaturated value tones down all relevant colour values. It still combines an accented background with an appropriate background, yet its overall impression is very subtle. Refined changes are a bit more intense to fulfil their intended function, though still less saturated than default.

While fg-only will remove all accented backgrounds and instead rely on colour-coded text to denote changes. For instance, added lines use an intense green foreground, while their background is the same as the rest of the buffer. Word-wise highlights still use a background value which is, nonetheless, more subtle than its default equivalent.

Concerning magit, an extra set of tweaks are introduced for the effect of highlighting the current diff hunk, so as to remain consistent with the overall experience of that mode. Expect changes that are consistent with the overall intent of the aforementioned.

4.13 Option for org-mode block styles

Symbol names:

  • modus-operandi-theme-org-blocks
  • modus-vivendi-theme-org-blocks

Possible values:

  1. nil (default)
  2. greyscale
  3. rainbow

The default is to use the same background as the rest of the buffer for the contents of the block.

A value of greyscale will apply a subtle neutral grey background to the block’s contents. It will also extend to the edge of the window the background of the “begin” and “end” block delimiter lines (only relevant for Emacs versions >= 27 where the ’extend’ keyword is recognised by set-face-attribute).

While rainbow will instead use an accented background for the contents of the block. The exact colour will depend on the programming language and is controlled by the org-src-block-faces variable (refer to the theme’s source code for the current association list). This is most suitable for users who work on literate programming documents that mix and match several languages.

Note that the “rainbow” blocks may require you to also reload the major-mode so that the colours are applied properly: use M-x org-mode or M-x org-mode-restart to refresh the buffer. Or start typing in each code block (inefficient at scale, but it still works).

4.14 Option for headings' overall style

This is defined as an alist and, therefore, uses a different approach than other customisation options documented in this manual.

Symbol names:

  • modus-operandi-theme-headings
  • modus-vivendi-theme-headings

Possible values, which can be specified for each heading level (examples further below):

  • t (default style)
  • no-bold
  • line
  • line-no-bold
  • rainbow
  • rainbow-line
  • rainbow-line-no-bold
  • rainbow-highlight
  • rainbow-highlight-no-bold
  • section
  • section-no-bold
  • rainbow-section
  • rainbow-section-no-bold

To control faces per level from 1-8, use something like this (same for modus-vivendi-theme-headings):

(setq modus-operandi-theme-headings
      '((1 . highlight)
        (2 . line)
        (t . rainbow-line-no-bold)))

The above uses the highlight value for heading levels 1 and the line for headings 2. All other levels fall back to rainbow-line-no-bold.

To set a uniform value for all heading levels, use this pattern:

(setq modus-operandi-theme-headings
      '((t . rainbow-line-no-bold)))

The default style for headings uses a fairly desaturated foreground value in combination with a bold typographic weight. To specify this style for a given level N (assuming you wish to have another fallback option), just specify the value t like this:

(setq modus-operandi-theme-headings
      '((1 . t)
        (2 . line)
        (t . rainbow-line-no-bold)))

A description of all other possible values:

  • no-bold retains the default text colour while removing the typographic weight.
  • line is the same as the default plus an overline over the heading.
  • line-no-bold is the same as line without bold weight.
  • rainbow uses a more colourful foreground in combination with bold weight.
  • rainbow-line is the same as rainbow plus an overline.
  • rainbow-line-no-bold is the same as rainbow-line without the bold weight.
  • highlight retains the default style of a fairly desaturated foreground combined with a bold weight and add to it a subtle accented background.
  • highlight-no-bold is the same as highlight without a bold weight.
  • rainbow-highlight is the same as highlight but with a more colourful foreground.
  • rainbow-highlight-no-bold is the same as rainbow-highlight without a bold weight.
  • section retains the default looks and adds to them both an overline and a slightly accented background. It is, in effect, a combination of the line and highlight values.
  • section-no-bold is the same as section without a bold weight.
  • rainbow-section is the same as section but with a more colourful foreground.
  • rainbow-section-no-bold is the same as rainbow-section without a bold weight.“

4.15 Option for scaled headings

Symbol names:

  • modus-operandi-theme-scale-headings
  • modus-vivendi-theme-scale-headings

Possible values:

  1. nil (default)
  2. t

Make headings larger in height relative to the main text. This is noticeable in modes like Org. The default is to use the same size for headings and body copy.

4.15.1 Control the scale of headings

In addition to toggles for enabling scaled headings, users can also specify a number of their own.

  • If it is a floating point, say, 1.5, it is interpreted as a multiple of the base font size. This is the recommended method.
  • If it is an integer, it is read as an absolute font height. The number is basically the point size multiplied by a hundred. So if you want it to be 18pt you must pass 180. Please understand that setting an absolute value is discouraged, as it will break the layout when you try to change font sizes with the built-in text-scale-adjust command (see Font configurations).

Below are the variables in their default values, using the floating point paradigm. The numbers are very conservative, but you are free to change them to your liking, such as 1.2, 1.4, 1.6, 1.8, 2.0—or use a resource for finding a consistent scale:

(setq modus-operandi-theme-scale-1 1.05
      modus-operandi-theme-scale-2 1.1
      modus-operandi-theme-scale-3 1.15
      modus-operandi-theme-scale-4 1.2
      modus-operandi-theme-scale-5 1.3)

(setq modus-vivendi-theme-scale-1 1.05
      modus-vivendi-theme-scale-2 1.1
      modus-vivendi-theme-scale-3 1.15
      modus-vivendi-theme-scale-4 1.2
      modus-vivendi-theme-scale-5 1.3)

Note that in Org, scaling only increases the size of the heading, but not of keywords that are added to it, like “TODO”. This is outside the control of the themes and I am not aware of any way to make such keywords scale accordingly without patching upstream Org (see issue 37 in the themes’ issue tracker).

4.16 Option for variable-pitch font in headings

Symbol names:

  • modus-operandi-theme-variable-pitch-headings
  • modus-vivendi-theme-variable-pitch-headings

Possible values:

  1. nil (default)
  2. t

Choose to apply a proportionately spaced, else “variable-pitch”, typeface to headings (such as in Org mode). The default is to use the main font family.

Font configurations for Org (and others).

5 Advanced customisation (do-it-yourself)

Unlike the predefined customisation options which follow a straightforward pattern of allowing the user to quickly specify their preference, the themes also provide a more flexible, albeit difficult, mechanism to control things with precision (see Customisation Options).

This section is of interest only to users who are prepared to maintain their own local tweaks and who are willing to deal with any possible incompatibilities between versioned releases of the themes. As such, they are labelled as “do-it-yourself” or “DIY”.

5.1 Full access to the themes' palette

The variables are:

  • modus-operandi-theme-override-colors-alist
  • modus-vivendi-theme-override-colors-alist

Users can specify an association list that maps the names of colour variables to hexadecimal RGB values (in the form of #RRGGBB). This means that it is possible to override the entire palette or subsets thereof (see the source code for the actual names and values).

Example:

;; Redefine the values of those three variables for the given theme
(setq modus-vivendi-theme-override-colors-alist
      '(("magenta" . "#ffaabb")
        ("magenta-alt" . "#ee88ff")
        ("magenta-alt-other" . "#bbaaff")))

If you want to be creative, you can define a minor mode that refashions the themes on demand. The following is a minor mode that gets activated on demand. We combine it with the function to switch between Modus Operandi and Modus Vivendi (see Toggle between the themes on demand for a basic command, and/or Configure options prior to loading for a more comprehensive setup).

(define-minor-mode modus-themes-alt-mode
  "Override Modus themes' palette variables with custom values.

This is intended as a proof-of-concept.  It is, nonetheless, a
perfectly accessible alternative, conforming with the design
principles of the Modus themes.  It still is not as good as the
default colours."
  :init-value nil
  :global t
  (if modus-themes-alt-mode
      (setq modus-operandi-theme-override-colors-alist
            '(("bg-main" . "#fefcf4")
              ("bg-dim" . "#faf6ef")
              ("bg-alt" . "#f7efe5")
              ("bg-hl-line" . "#f4f0e3")
              ("bg-active" . "#e8dfd1")
              ("bg-inactive" . "#f6ece5")
              ("bg-region" . "#c6bab1")
              ("bg-header" . "#ede3e0")
              ("bg-tab-bar" . "#dcd3d3")
              ("bg-tab-active" . "#fdf6eb")
              ("bg-tab-inactive" . "#c8bab8")
              ("fg-unfocused" . "#55556f"))
            modus-vivendi-theme-override-colors-alist
            '(("bg-main" . "#100b17")
              ("bg-dim" . "#161129")
              ("bg-alt" . "#181732")
              ("bg-hl-line" . "#191628")
              ("bg-active" . "#282e46")
              ("bg-inactive" . "#1a1e39")
              ("bg-region" . "#393a53")
              ("bg-header" . "#202037")
              ("bg-tab-bar" . "#262b41")
              ("bg-tab-active" . "#120f18")
              ("bg-tab-inactive" . "#3a3a5a")
              ("fg-unfocused" . "#9a9aab")))
    (setq modus-operandi-theme-override-colors-alist nil
          modus-vivendi-theme-override-colors-alist nil)))

(defun modus-themes-toggle (&optional arg)
  "Toggle between `modus-operandi' and `modus-vivendi' themes.

With optional \\[universal-argument] prefix, enable
`modus-themes-alt-mode' for the loaded theme."
  (interactive "P")
  (if arg
      (modus-themes-alt-mode 1)
    (modus-themes-alt-mode -1))
  (if (eq (car custom-enabled-themes) 'modus-operandi)
      (progn
        (disable-theme 'modus-operandi)
        (load-theme 'modus-vivendi t))
    (disable-theme 'modus-vivendi)
    (load-theme 'modus-operandi t)))

5.2 Font configurations for Org (and others)

The themes are designed to cope well with mixed font settings. Currently this applies to org-mode and markdown-mode.

In practice it means that the user can safely opt for a more prose-friendly proportionately spaced typeface as their default, while letting spacing-sensitive elements like tables and inline code always use a monospaced font, by inheriting from the fixed-pitch face.

Users can try the built-in M-x variable-pitch-mode to see the effect in action.

To make everything use your desired font families, you need to configure the variable-pitch (proportional spacing) and fixed-pitch (monospaced) faces respectively. It may also be convenient to set your main typeface by configuring the default face the same way.

Put something like this in your initialisation file (make sure to read the documentation of set-face-attribute, with M-x describe-function):

;; Main typeface
(set-face-attribute 'default nil :family "DejaVu Sans Mono" :height 110)

;; Proportionately spaced typeface
(set-face-attribute 'variable-pitch nil :family "DejaVu Serif" :height 1.0)

;; Monospaced typeface
(set-face-attribute 'fixed-pitch nil :family "DejaVu Sans Mono" :height 1.0)

Note the differences in the :height property. The default face must specify an absolute value, which is the point size × 10. So if you want to use a font at point size 11, you set the height at 110.4 Whereas every other face must have a value that is relative to the default, represented as a floating point (if you use an integer, say, 15 then that means an absolute height). This is of paramount importantance: it ensures that all fonts can scale gracefully when using something like the text-scale-adjust command which only operates on the base font size (i.e. the default face’s absolute height).

An alternative syntax for the default face, which the author of this documents prefers, is to pass all typeface parameters directly to a font property.5 Note that here we use a standard point size:

(set-face-attribute 'default nil :font "DejaVu Sans Mono-11")

Again, remember to only ever specify an absolute height for the default.

5.3 Org user faces (DIY)

Users of org-mode have the option to configure various keywords and priority cookies to better match their workflow. User options are org-todo-keyword-faces and org-priority-faces.

As those are meant to be custom faces, it would be futile to have the themes try to guess what each user would want to use, which keywords to target, and so on. Instead, we can provide guidelines on how to customise things to one’s liking with the intent to retain the overall aesthetics of the theme.

Please bear in mind that the end result of those is not controlled by the active theme but by how Org maps faces to its constructs. Editing those while org-mode is active requires M-x org-mode-restart for changes to take effect.

Let us assume you wish to visually differentiate your keywords. You have something like this:

(setq org-todo-keywords
      '((sequence "TODO(t)" "|" "DONE(D)" "CANCEL(C)")
        (sequence "MEET(m)" "|" "MET(M)")
        (sequence "STUDY(s)" "|" "STUDIED(S)")
        (sequence "WRITE(w)" "|" "WROTE(W)")))

You could then use a variant of the following to inherit from a face that uses the styles you want and also to preserve the properties applied by the org-todo face:

(setq org-todo-keyword-faces
      '(("MEET" . '(font-lock-preprocessor-face org-todo))
        ("STUDY" . '(font-lock-variable-name-face org-todo))
        ("WRITE" . '(font-lock-type-face org-todo))))

This will refashion the keywords you specify, while letting the other items in org-todo-keywords use their original styles (which are defined in the org-todo and org-done faces).

If you want back the defaults, try specifying just the org-todo face (or use org-done if the meaning of the keywords you use demands as much):

(setq org-todo-keyword-faces
      '(("MEET" . org-todo)
        ("STUDY" . org-todo)
        ("WRITE" . org-todo)))

When you inherit from multiple faces, you need to quote the list as shown further above. The order is important: the last item is applied over the previous ones. If you do not want to blend multiple faces, you do not need a quoted list. A pattern of keyword . face would suffice.

Both approaches can be used simultaneously, as illustrated in this configuration of the priority cookies:

(setq org-priority-faces
      '((?A . '(org-scheduled-today org-priority))
        (?B . org-priority)
        (?C . '(shadow org-priority))))

To find all the faces that are loaded in your current Emacs session, use M-x list-faces-display. Also try M-x describe-variable and then specify the name of each of those Org variables demonstrated above. Their documentation strings will offer you further guidance.

Also consider reading the “Notes for aspiring Emacs theme developers”, published on 2020-08-28 by Protesilaos Stavrou: https://protesilaos.com/codelog/2020-08-28-notes-emacs-theme-devs/.

6 Face coverage

Modus Operandi and Modus Vivendi try to provide as close to full face coverage as possible. This is necessary to ensure a consistently accessible reading experience across all possible interfaces.

6.1 Full support for packages or face groups

This list will always be updated to reflect the current state of the project. The idea is to offer an overview of the known status of all affected face groups. The items with an appended asterisk * tend to have lots of extensions, so the “full support” may not be 100% true…

  • ace-window
  • ag
  • alert
  • all-the-icons
  • annotate
  • anzu
  • apropos
  • apt-sources-list
  • artbollocks-mode
  • auctex and TeX
  • auto-dim-other-buffers
  • avy
  • awesome-tray
  • binder
  • bm
  • bongo
  • boon
  • breakpoint (provided by the built-in gdb-mi.el library)
  • buffer-expose
  • calendar and diary
  • calfw
  • centaur-tabs
  • change-log and log-view (such as vc-print-log and vc-print-root-log)
  • cider
  • circe
  • color-rg
  • column-enforce-mode
  • company-mode*
  • company-posframe
  • compilation-mode
  • completions
  • counsel*
  • counsel-css
  • counsel-notmuch
  • counsel-org-capture-string
  • cov
  • cperl-mode
  • csv-mode
  • ctrlf
  • custom (M-x customize)
  • dap-mode
  • dashboard (emacs-dashboard)
  • deadgrep
  • debbugs
  • define-word
  • deft
  • dictionary
  • diff-hl
  • diff-mode
  • dim-autoload
  • dired
  • dired-async
  • dired-git
  • dired-git-info
  • dired-narrow
  • dired-subtree
  • diredfl
  • disk-usage
  • doom-modeline
  • dynamic-ruler
  • easy-jekyll
  • easy-kill
  • ebdb
  • ediff
  • eglot
  • el-search
  • eldoc-box
  • elfeed
  • elfeed-score
  • emms
  • enhanced-ruby-mode
  • epa
  • equake
  • erc
  • eros
  • ert
  • eshell
  • eshell-fringe-status
  • eshell-git-prompt
  • eshell-prompt-extras (epe)
  • eshell-syntax-highlighting
  • evil* (evil-mode)
  • evil-goggles
  • evil-visual-mark-mode
  • eww
  • eyebrowse
  • fancy-dabbrev
  • flycheck
  • flycheck-indicator
  • flycheck-posframe
  • flymake
  • flyspell
  • flyspell-correct
  • flx
  • freeze-it
  • frog-menu
  • focus
  • fold-this
  • font-lock (generic syntax highlighting)
  • forge
  • fountain (fountain-mode)
  • geiser
  • git-commit
  • git-gutter (and variants)
  • git-lens
  • git-rebase
  • git-timemachine
  • git-walktree
  • gnus
  • golden-ratio-scroll-screen
  • helm*
  • helm-ls-git
  • helm-switch-shell
  • helm-xref
  • helpful
  • highlight-blocks
  • highlight-defined
  • highlight-escape-sequences (hes-mode)
  • highlight-indentation
  • highlight-numbers
  • highlight-symbol
  • highlight-tail
  • highlight-thing
  • hl-defined
  • hl-fill-column
  • hl-line-mode
  • hl-todo
  • hydra
  • hyperlist
  • ibuffer
  • icomplete
  • icomplete-vertical
  • ido-mode
  • iedit
  • iflipb
  • imenu-list
  • indium
  • info
  • info-colors
  • interaction-log
  • ioccur
  • isearch, occur, etc.
  • ivy*
  • ivy-posframe
  • jira (org-jira)
  • journalctl-mode
  • js2-mode
  • julia
  • jupyter
  • kaocha-runner
  • keycast
  • line numbers (display-line-numbers-mode and global variant)
  • lsp-mode
  • lsp-ui
  • magit
  • magit-imerge
  • man
  • markdown-mode
  • markup-faces (adoc-mode)
  • mentor
  • messages
  • minibuffer-line
  • minimap
  • modeline
  • mood-line
  • moody
  • mu4e
  • mu4e-conversation
  • multiple-cursors
  • neotree
  • no-emoji
  • notmuch
  • num3-mode
  • nxml-mode
  • objed
  • orderless
  • org*
  • org-journal
  • org-noter
  • org-pomodoro
  • org-recur
  • org-roam
  • org-superstar
  • org-table-sticky-header
  • org-treescope
  • origami
  • outline-mode
  • outline-minor-faces
  • package (M-x list-packages)
  • page-break-lines
  • paradox
  • paren-face
  • parrot
  • pass
  • persp-mode
  • perspective
  • phi-grep
  • phi-search
  • pkgbuild-mode
  • pomidor
  • powerline
  • powerline-evil
  • proced
  • prodigy
  • racket-mode
  • rainbow-blocks
  • rainbow-identifiers
  • rainbow-delimiters
  • rcirc
  • regexp-builder (also known as re-builder)
  • rg (rg.el)
  • ripgrep
  • rmail
  • ruler-mode
  • sallet
  • selectrum
  • semantic
  • sesman
  • shell-script-mode
  • show-paren-mode
  • side-notes
  • skewer-mode
  • smart-mode-line
  • smartparens
  • smerge
  • spaceline
  • speedbar
  • spell-fu
  • stripes
  • suggest
  • switch-window
  • swiper
  • swoop
  • sx
  • symbol-overlay
  • syslog-mode
  • table (built-in table.el)
  • telephone-line
  • term
  • tomatinho
  • transient (pop-up windows such as Magit’s)
  • trashed
  • treemacs
  • tty-menu
  • tuareg
  • undo-tree
  • vc (built-in mode line status for version control)
  • vc-annotate (C-x v g)
  • vdiff
  • vimish-fold
  • visible-mark
  • visual-regexp
  • volatile-highlights
  • vterm
  • wcheck-mode
  • web-mode
  • wgrep
  • which-function-mode
  • which-key
  • whitespace-mode
  • window-divider-mode
  • winum
  • writegood-mode
  • woman
  • xah-elisp-mode
  • xref
  • xterm-color (and ansi-colors)
  • yaml-mode
  • yasnippet
  • ztree

Plus many other miscellaneous faces that are provided by the upstream GNU Emacs distribution.

6.2 Covered indirectly

These do not require any extra styles because they are configured to inherit from some basic faces. Please confirm.

  • edit-indirect
  • perl-mode
  • php-mode
  • swift-mode

6.3 Will NOT be supported

I have thus far identified a single package that does fit into the overarching objective of this project: solaire. It basically tries to cast a less intense background on the main file-visiting buffers, so that secondary elements like sidebars can have the default (pure white/black) background.

I will only cover this package if it ever supports the inverse effect: less intense colours (but still accessible) for supportive interfaces and the intended styles for the content you are actually working on.

7 Notes for individual packages

This section covers information that may be of interest to users of individual packages.

7.1 Note for ERC escaped colour sequences

The built-in IRC client erc has the ability to colourise any text using escape sequences that start with ^C (inserted with C-q C-c) and are followed by a number for the foreground and background.6 Possible numbers are 0-15, with the first entry being the foreground and the second the background, separated by a comma. Like this ^C1,6. The minimum setup is this:

(add-to-list 'erc-modules 'irccontrols)
(setq erc-interpret-controls-p t
      erc-interpret-mirc-color t)

As this allows users to make arbitrary combinations, it is impossible to guarantee a consistently high contrast ratio. All we can we do is provide guidance on the combinations that satisfy the accessibility standard of the themes:

Modus Operandi
Use foreground colour 1 for all backgrounds from 2-15. Like so: C-q C-c1,N where N is the background.
Modus Vivendi
Use foreground colour 0 for all backgrounds from 2-13. Use foreground 1 for backgrounds 14, 15.

Colours 0 and 1 are white and black respectively. So combine them together, if you must.

7.2 Note for powerline or spaceline

Both Powerline and Spaceline package users will likely need to use the command powerline-reset whenever they make changes to their themes and/or modeline setup.

7.3 Note on shr colours

Emacs’ HTML rendering mechanism (shr) may need explicit configuration to respect the theme’s colours instead of whatever specifications the webpage provides. Consult C-h v shr-use-colors.

7.4 Note for Helm grep

There is one face from the Helm package that is meant to highlight the matches of a grep or grep-like command (ag or ripgrep). It is helm-grep-match. However, this face can only apply when the user does not pass --color=always as a command-line option for their command.

Here is the docstring for that face, which is defined in the helm-grep.el library (view a library with M-x find-library).

Face used to highlight grep matches. Have no effect when grep backend use “–color=”

The user must either remove --color from the flags passed to the grep function, or explicitly use --color=never (or equivalent). Helm provides user-facing customisation options for controlling the grep function’s parameters, such as helm-grep-default-command and helm-grep-git-grep-command.

When --color=always is in effect, the grep output will use red text in bold letter forms to present the matching part in the list of candidates. That style still meets the contrast ratio target of >= 7:1 (accessibility standard WCAG AAA), because it draws the reference to ANSI colour number 1 (red) from the already-supported array of ansi-color-names-vector.

7.5 Note on vc-annotate-background-mode

Due to the unique way vc-annotate (C-x v g) applies colours, support for its background mode (vc-annotate-background-mode) is disabled at the theme level.

Normally, such a drastic measure should not belong in a theme: assuming the user’s preferences is bad practice. However, it has been deemed necessary in the interest of preserving colour contrast accessibility while still supporting a useful built-in tool.

If there actually is a way to avoid such a course of action, without prejudice to the accessibility standard of this project, then please report as much or send patches (see Contributing).

8 Contributing

This section documents the canonical sources of the themes and the ways in which you can contribute to their ongoing development.

8.1 Sources of the themes

The modus-operandi and modus-vivendi themes are built into Emacs. Currently they are in the project’s master branch, which is tracking the nominal development release target of 28.0.50.

The source code of the themes is available on Gitlab, for the time being. A mirror on Github is also on offer.

An HTML version of this manual is available as an extension to the author’s personal website (does not rely on any non-free code).

8.2 Issues you can help with

A few tasks you can help with:

  • Suggest refinements to packages that are covered.
  • Report packages not covered thus far.
  • Report bugs, inconsistencies, shortcomings.
  • Help expand the documentation of covered-but-not-styled packages.
  • Suggest refinements to the colour palette.
  • Help expand this document or any other piece of documentation.
  • Merge requests for code refinements.

Patches require copyright assignment to the FSF.

It would be great if your feedback also includes some screenshots, GIFs, or short videos, as well as further instructions to reproduce a given setup. Though this is not a requirement.

Whatever you do, bear in mind the overarching objective of the Modus themes: to keep a contrast ratio that is greater or equal to 7:1 between background and foreground colours. If a compromise is ever necessary between aesthetics and accessibility, it shall always be made in the interest of the latter.

8.3 Patches require copyright assignment to the FSF

Code contributions are most welcome. For any major edit (more than 15 lines, or so, in aggregate per person), you need to make a copyright assignment to the Free Software Foundation. This is necessary because the themes are part of the upstream Emacs distribution: the FSF must at all times be in a position to enforce the GNU General Public License.

Copyright assignment is a simple process. Check the request form. You must write an email to the address mentioned in the form and then wait for the FSF to send you a legal agreement. Sign the document and file it back to them. This could all happen via email and take about a week.

You are encouraged to go through this process. You only need to do it once. It will allow you to make contributions to Emacs in general.

9 Acknowledgements

The Modus themes are a collective effort. Every contribution counts.

Author/maintainer
Protesilaos Stavrou.
Code contributions
Anders Johansson, Basil L. Contovounisios, Markus Beppler, Matthew Stevenson.
Ideas and user feedback
Aaron Jensen, Adam Spiers, Alex Griffin, Alex Peitsinis, Alexey Shmalko, Anders Johansson, André Alexandre Gomes, Arif Rezai, Basil L. Contovounisios, Damien Cassou, Dario Gjorgjevski, David Edmondson, Davor Rotim, Divan Santana, Gerry Agbobada, Gianluca Recchia, Len Trigg, Manuel Uberti, Mark Burton, Markus Beppler, Michael Goldenberg, Murilo Pereira, Nicolas De Jaeghere, Pierre Téchoueyres, Ryan Phillips, Shreyas Ragavan, Tassilo Horn, Thibaut Verron, Trey Merkley, Uri Sharf, Utkarsh Singh, Vincent Foley. As well as users: Ben, Fourchaux, Fredrik, Moesasji, TheBlob42, dinko, doolio, jixiuf, okamsn, tycho garen.
Packaging
Dhavan Vaidya (Debian), Stefan Kangas (core Emacs), Stefan Monnier (GNU Elpa).
Inspiration for certain features
Fabrice Niessen (leuven-theme), Bozhidar Batsov (zenburn-theme).

10 Meta

If you are curious about the principles that govern the development of this project read the essay On the design of the Modus themes (2020-03-17).

Here are some more publications for those interested in the kind of work that goes into this project:

11 External projects (ports)

The present section documents projects that extend the scope of the Modus themes. The following list will be updated whenever relevant information is brought to my attention. If you already have or intend to produce such a port, feel welcome to contact me.

Modus exporter
This is an Elisp library written by Simon Pugnet. Licensed under the terms of the GNU General Public License. It is meant to capture the colour values of the active Modus theme (Operandi or Vivendi) and output it as a valid theme for some other application.

12 GNU Free Documentation License

                GNU Free Documentation License
                 Version 1.3, 3 November 2008


 Copyright (C) 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
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 Everyone is permitted to copy and distribute verbatim copies
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   Document (all of its principal authors, if it has fewer than five),
   unless they release you from this requirement.
C. State on the Title page the name of the publisher of the
   Modified Version, as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications
   adjacent to the other copyright notices.
F. Include, immediately after the copyright notices, a license notice
   giving the public permission to use the Modified Version under the
   terms of this License, in the form shown in the Addendum below.
G. Preserve in that license notice the full lists of Invariant Sections
   and required Cover Texts given in the Document's license notice.
H. Include an unaltered copy of this License.
I. Preserve the section Entitled "History", Preserve its Title, and add
   to it an item stating at least the title, year, new authors, and
   publisher of the Modified Version as given on the Title Page.  If
   there is no section Entitled "History" in the Document, create one
   stating the title, year, authors, and publisher of the Document as
   given on its Title Page, then add an item describing the Modified
   Version as stated in the previous sentence.
J. Preserve the network location, if any, given in the Document for
   public access to a Transparent copy of the Document, and likewise
   the network locations given in the Document for previous versions
   it was based on.  These may be placed in the "History" section.
   You may omit a network location for a work that was published at
   least four years before the Document itself, or if the original
   publisher of the version it refers to gives permission.
K. For any section Entitled "Acknowledgements" or "Dedications",
   Preserve the Title of the section, and preserve in the section all
   the substance and tone of each of the contributor acknowledgements
   and/or dedications given therein.
L. Preserve all the Invariant Sections of the Document,
   unaltered in their text and in their titles.  Section numbers
   or the equivalent are not considered part of the section titles.
M. Delete any section Entitled "Endorsements".  Such a section
   may not be included in the Modified Version.
N. Do not retitle any existing section to be Entitled "Endorsements"
   or to conflict in title with any Invariant Section.
O. Preserve any Warranty Disclaimers.

If the Modified Version includes new front-matter sections or
appendices that qualify as Secondary Sections and contain no material
copied from the Document, you may at your option designate some or all
of these sections as invariant.  To do this, add their titles to the
list of Invariant Sections in the Modified Version's license notice.
These titles must be distinct from any other section titles.

You may add a section Entitled "Endorsements", provided it contains
nothing but endorsements of your Modified Version by various
parties--for example, statements of peer review or that the text has
been approved by an organization as the authoritative definition of a
standard.

You may add a passage of up to five words as a Front-Cover Text, and a
passage of up to 25 words as a Back-Cover Text, to the end of the list
of Cover Texts in the Modified Version.  Only one passage of
Front-Cover Text and one of Back-Cover Text may be added by (or
through arrangements made by) any one entity.  If the Document already
includes a cover text for the same cover, previously added by you or
by arrangement made by the same entity you are acting on behalf of,
you may not add another; but you may replace the old one, on explicit
permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License
give permission to use their names for publicity for or to assert or
imply endorsement of any Modified Version.


5. COMBINING DOCUMENTS

You may combine the Document with other documents released under this
License, under the terms defined in section 4 above for modified
versions, provided that you include in the combination all of the
Invariant Sections of all of the original documents, unmodified, and
list them all as Invariant Sections of your combined work in its
license notice, and that you preserve all their Warranty Disclaimers.

The combined work need only contain one copy of this License, and
multiple identical Invariant Sections may be replaced with a single
copy.  If there are multiple Invariant Sections with the same name but
different contents, make the title of each such section unique by
adding at the end of it, in parentheses, the name of the original
author or publisher of that section if known, or else a unique number.
Make the same adjustment to the section titles in the list of
Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections Entitled "History"
in the various original documents, forming one section Entitled
"History"; likewise combine any sections Entitled "Acknowledgements",
and any sections Entitled "Dedications".  You must delete all sections
Entitled "Endorsements".


6. COLLECTIONS OF DOCUMENTS

You may make a collection consisting of the Document and other
documents released under this License, and replace the individual
copies of this License in the various documents with a single copy
that is included in the collection, provided that you follow the rules
of this License for verbatim copying of each of the documents in all
other respects.

You may extract a single document from such a collection, and
distribute it individually under this License, provided you insert a
copy of this License into the extracted document, and follow this
License in all other respects regarding verbatim copying of that
document.


7. AGGREGATION WITH INDEPENDENT WORKS

A compilation of the Document or its derivatives with other separate
and independent documents or works, in or on a volume of a storage or
distribution medium, is called an "aggregate" if the copyright
resulting from the compilation is not used to limit the legal rights
of the compilation's users beyond what the individual works permit.
When the Document is included in an aggregate, this License does not
apply to the other works in the aggregate which are not themselves
derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one half of
the entire aggregate, the Document's Cover Texts may be placed on
covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic form.
Otherwise they must appear on printed covers that bracket the whole
aggregate.


8. TRANSLATION

Translation is considered a kind of modification, so you may
distribute translations of the Document under the terms of section 4.
Replacing Invariant Sections with translations requires special
permission from their copyright holders, but you may include
translations of some or all Invariant Sections in addition to the
original versions of these Invariant Sections.  You may include a
translation of this License, and all the license notices in the
Document, and any Warranty Disclaimers, provided that you also include
the original English version of this License and the original versions
of those notices and disclaimers.  In case of a disagreement between
the translation and the original version of this License or a notice
or disclaimer, the original version will prevail.

If a section in the Document is Entitled "Acknowledgements",
"Dedications", or "History", the requirement (section 4) to Preserve
its Title (section 1) will typically require changing the actual
title.


9. TERMINATION

You may not copy, modify, sublicense, or distribute the Document
except as expressly provided under this License.  Any attempt
otherwise to copy, modify, sublicense, or distribute it is void, and
will automatically terminate your rights under this License.

However, if you cease all violation of this License, then your license
from a particular copyright holder is reinstated (a) provisionally,
unless and until the copyright holder explicitly and finally
terminates your license, and (b) permanently, if the copyright holder
fails to notify you of the violation by some reasonable means prior to
60 days after the cessation.

Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.

Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License.  If your rights have been terminated and not permanently
reinstated, receipt of a copy of some or all of the same material does
not give you any rights to use it.


10. FUTURE REVISIONS OF THIS LICENSE

The Free Software Foundation may publish new, revised versions of the
GNU Free Documentation License from time to time.  Such new versions
will be similar in spirit to the present version, but may differ in
detail to address new problems or concerns.  See
https://www.gnu.org/licenses/.

Each version of the License is given a distinguishing version number.
If the Document specifies that a particular numbered version of this
License "or any later version" applies to it, you have the option of
following the terms and conditions either of that specified version or
of any later version that has been published (not as a draft) by the
Free Software Foundation.  If the Document does not specify a version
number of this License, you may choose any version ever published (not
as a draft) by the Free Software Foundation.  If the Document
specifies that a proxy can decide which future versions of this
License can be used, that proxy's public statement of acceptance of a
version permanently authorizes you to choose that version for the
Document.

11. RELICENSING

"Massive Multiauthor Collaboration Site" (or "MMC Site") means any
World Wide Web server that publishes copyrightable works and also
provides prominent facilities for anybody to edit those works.  A
public wiki that anybody can edit is an example of such a server.  A
"Massive Multiauthor Collaboration" (or "MMC") contained in the site
means any set of copyrightable works thus published on the MMC site.

"CC-BY-SA" means the Creative Commons Attribution-Share Alike 3.0
license published by Creative Commons Corporation, a not-for-profit
corporation with a principal place of business in San Francisco,
California, as well as future copyleft versions of that license
published by that same organization.

"Incorporate" means to publish or republish a Document, in whole or in
part, as part of another Document.

An MMC is "eligible for relicensing" if it is licensed under this
License, and if all works that were first published under this License
somewhere other than this MMC, and subsequently incorporated in whole or
in part into the MMC, (1) had no cover texts or invariant sections, and
(2) were thus incorporated prior to November 1, 2008.

The operator of an MMC Site may republish an MMC contained in the site
under CC-BY-SA on the same site at any time before August 1, 2009,
provided the MMC is eligible for relicensing.


ADDENDUM: How to use this License for your documents

To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and
license notices just after the title page:

    Copyright (c)  YEAR  YOUR NAME.
    Permission is granted to copy, distribute and/or modify this document
    under the terms of the GNU Free Documentation License, Version 1.3
    or any later version published by the Free Software Foundation;
    with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
    A copy of the license is included in the section entitled "GNU
    Free Documentation License".

If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the "with...Texts." line with this:

    with the Invariant Sections being LIST THEIR TITLES, with the
    Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST.

If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.

If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License,
to permit their use in free software.

Footnotes:

2

Contributed directly by André Alexandre Gomes https://gitlab.com/aadcg.

3

The defmacro and dolist method was contributed on Reddit by user b3n https://www.reddit.com/r/emacs/comments/gqsz8u/weekly_tipstricketc_thread/fsfakhg/.

4

:height values do not need to be rounded to multiples of ten: the likes of 115 are perfectly valid—some typefaces will change to account for those finer increments.

5

Has the benefit of accepting fontconfig parameters (GNU/Linux), such as "DejaVu Sans Mono-11:hintstyle=hintslight:autohint=false". https://www.freedesktop.org/software/fontconfig/fontconfig-user.html

6

This page explains the basics, though it is not specific to Emacs: https://www.mirc.com/colors.html