🌈 I provide private lessons on Emacs, Linux, and Life in general: https://protesilaos.com/coach/.

Emacs: modus-themes version 4.0.0

I just published the latest stable release of the Modus themes. The change log entry is reproduced further below. It is a long read. For any questions, feel welcome to contact me.

I will now patch emacs.git so please wait a little longer for the updates to trickle down to you.


This is the biggest release in the history of the project. Previously, a new version would consist of about 100 commits to the Git repository. This one includes 400+ of them in the span of one month. The out-of-the-box looks of the themes are largely the same as before, though I have made a lot of internal changes that affect how the themes are instantiated and customised.

As part of this development cycle, I produced publications informing users of the upcoming changes, while demonstrating the new feature of overriding the colour palette and its semantic mappings.

I did this in the hope of preparing users for the refactored Modus themes, though I understand that not everyone has had the chance to consult those entries. The general idea is that old custom code will not work and most user options are either removed or confined to a more precise scope.

Custom code will not work because the named colours of the palettes have changed. Many user options are made redundant by the new overrides’ system. Specifically, if an option pertains to colouration, it is now done via overrides instead of the old method of me hardcoding styles (e.g. for stuff like “rainbow” headings).

More details below. This is a long entry. Please take your time to study it before upgrading to the new version of the themes.

There now are six Modus themes for more legibility needs

Quoting from the manual’s “Overview” section:

The Modus themes consist of six themes, divided into three subgroups.

  • Main themes: modus-operandi is the project’s main light theme, while modus-vivendi is its dark counterpart. These two themes are part of the project since its inception. They are designed to cover a broad range of needs and are, in the opinion of the author, the reference for what a highly legible “default” theme should look like.

  • Tinted themes: modus-operandi-tinted and modus-vivendi-tinted are variants of the two main themes. They slightly tone down the intensity of the background and provide a bit more color variety. modus-operandi-tinted has a set of base tones that are shades of light ochre (earthly colors), while modus-vivendi-tinted gives a night sky impression.

  • Deuteranopia themes: modus-operandi-deuteranopia and its companion modus-vivendi-deuteranopia are optimized for users with red-green color deficiency. This means that they do not use red and green hues for color-coding purposes, such as for diff removed and added lines. Instead, they implement colors that are discernible by users with deueteranopia or deuteranomaly (mostly yellow and blue hues).

All six themes will be included in Emacs 30 (modus-operandi and modus-vivendi are in Emacs since August 2020). I asked about it on the emacs-devel mailing list and received the approval of Eli Zaretskii, one of the Emacs maintainers. The full thread: https://lists.gnu.org/archive/html/emacs-devel/2022-12/msg00834.html.

New command to select one of the Modus themes

The modus-themes-select command uses minibuffer completion to load one of the six themes in the collection. Loading a Modus theme disables all other Modus themes.

NOTE that Emacs can load multiple themes, which typically produces undesirable results and undoes the work of the designer. Use the disable-theme command if you are trying other themes beside the Modus collection.

New user option to specify themes to toggle

The modus-themes-to-toggle is a variable that affects the command modus-themes-toggle. By default, the toggling happens between the modus-operandi and modus-vivendi themes, as was always the case. Though with the addition of new themes, it is possible to change this to something like:

(setq modus-themes-to-toggle '(modus-operandi-deuteranopia modus-vivendi-deuteranopia))

If modus-themes-to-toggle does not specify two Modus themes, the modus-themes-toggle command will prompt with completion for a theme among the collection (this is practically the same as the aforementioned modus-themes-select command).

Colour palettes and their overrides are much more powerful

In previous versions, there were options to override colour values. Those were difficult to use as they (i) required expertise on picking the correct values and (ii) it was not clear which colour was used where.

The new version broadens the colour palette to include named colours and semantic colour mappings. Named colours are associations between a symbol and a colour value, such as (blue-warmer "#354fcf"). While semantic colour mappings apply those named colours to specific constructs such as (heading-2 yellow-faint) for all level 2 headings.

What this means is that overrides can now be targeted at semantic mappings as well to refashion practically every aspect of the themes. The manual provides lots of examples that can be copied and used directly. For example, it is possible to change the sequence of colours in headings so that, say, there is a colour-coding that denotes depth. Links to relevant entries are included in this document.

The modus-themes-common-palette-overrides user option contains entries that are shared between all the themes. While there also exist theme-specific options such as modus-operandi-palette-overrides.

For technical insight into the palette overrides, consult the manual: https://protesilaos.com/emacs/modus-themes#h:34c7a691-19bb-4037-8d2f-67a07edab150.

For practical examples check “Stylistic variants using palette overrides” and its subsections: https://protesilaos.com/emacs/modus-themes#h:df1199d8-eaba-47db-805d-6b568a577bf3.

Preset overrides for faint or intense colouration

The palette overrides are comprehensive and can be tweaked in a detailed way. Still, users may prefer to use the presets for a “faint” or “intense” style. These presets showcase the new feature by styling elements that were previously not subject to configuration. They also provide the convenience of a common set of stylistic patterns.

Read the “Palette override presets” section in the manual for how to use and/or extend those: https://protesilaos.com/emacs/modus-themes#h:b0bc811c-227e-42ec-bf67-15e1f41eb7bc.

Named colours are more meaningful

In the past, the variants of the main accent colours were named like:

  • red
  • red-alt
  • red-alt-other

The improved naming scheme changes those to:

  • red
  • red-warmer
  • red-cooler

Semantically, the “warmer” variants have more yellow or red while the “cooler” ones have greater contribution of cyan or blue. As such, the user can expect green-warmer to be an olive green and green-cooler to be that of the pine (though olive trees can have blue-green colouration and pine trees can be “warmer”, but I digress).

Named colours can be previewed with the commands modus-themes-list-colors (alias modus-themes-preview-colors) and modus-themes-list-colors-current (alias modus-themes-preview-colors-current).

Those commands accept a C-u prefix argument, in which case they show the semantic colour mappings.

Rationalisation of the colour palette

In previous versions, there were a lot of named colours that were added ad-hoc, such as fg-special-cold and bg-special-calm-faint. There was no clear design pattern behind them, nor was it obvious where those colours should be used. Furthermore, there were colours that were reserved for the various permutations of user options.

This was too complex for users who wanted/needed to refashion aspects of the themes. It was also difficult to maintain.

The new palettes are more streamlined and their application is more predictable. This only matters to users who tweak the themes: it makes their life easier, although it does render inapplicable any previous custom code.

Deprecation of user options

The following subsections explain the topics in further detail. The general idea for this change is that palette overrides provide a more powerful, more flexible, and less complex alternative. The code base is considerably smaller.

With overrides, I can now provide support to cases such as:

  • Users who need different sets of greys as their monitor has inadequate colour reproduction (this is much more common than you think).
  • Users who want to make individual elements stand out, such as to turn the delimiters of Org source blocks (the #+begin_src and #+end_src lines) into, say, a shade of red.
  • Users who want to tone down the TODO and DONE keywords while making headings more colourful. Or the inverse, or any combination in-between the extremes.
  • Users who want Org property drawers to be more colourful but inline code to be faint.

You get the idea… All these and many more are now possible. Whereas in the past I would either have to tell people that it is not possible or hardcode a stylistic alternative via user options, thus further complicating the code base.

Catering to all those use-cases is important due to the maximalist scope of the Modus themes: I cannot tell people to use another theme, because here is where they come for their legibility needs. This is consistent with my experience that accessibility is not a one-size-fits-all and that the most accessible design is that which is flexible, ceteris paribus.

modus-themes-intense-mouseovers

This user option would amplify the background colour of mouse hover effects (technically, the highlight and mode-line-highlight faces). It always used a blue colour.

The same effect can now be achieved via overrides, except it is now possible to use any background colour or level of intensity that is provided by the themes’ palette. The manual provides concrete examples: https://protesilaos.com/emacs/modus-themes#h:b5cab69d-d7cb-451c-8ff9-1f545ceb6caf.

modus-themes-org-agenda

This was a complex user option that was hard to test, document, and maintain. Most aspects of the Org agenda can be affected via overrides, as demonstrated in the manual: https://protesilaos.com/emacs/modus-themes#h:a5af0452-a50f-481d-bf60-d8143f98105f.

modus-themes-fringes

This user option provided two shades of grey and the option for an invisible background for the Emacs fringe. The same and better can be done via overrides, as shown in the manual: https://protesilaos.com/emacs/modus-themes#h:c312dcac-36b6-4a1f-b1f5-ab1c9abe27b0.

modus-themes-lang-checkers

This was another complex user option that offered several stylistic variants of dubious value. The main problem it had is that linter highlights are often applied automatically, so any super intense style becomes unusable. Same when a file has lots of warnings/errors.

The semantic colour mappings I provide for this case are limited to underlines, which I think is the most usable/legible design. The manual provides concrete examples on how to tweak those: https://protesilaos.com/emacs/modus-themes#h:03dbd5af-6bae-475e-85a2-cec189f69598.

modus-themes-mode-line

Yet another very complex user option that I removed in the interest of maintainability. All its stylistic permutations (and more) for colours are possible via overrides:

It is also possible to add padding to the mode line, though I explain why this was always a dirty hack: https://protesilaos.com/emacs/modus-themes#h:5a0c58cc-f97f-429c-be08-927b9fbb0a9c.

modus-themes-diffs

I have redesigned all diff-related colours to improve their usability. They are less intense than before, but still stand out clearly. I am purposefully not documenting how to use overrides here as I want users to give this redesign a try. We can always document and refine things at a later point.

modus-themes-subtle-line-numbers

This was a simple, but ultimately very limited option. We can do much better with overrides because we can tweak every aspect of this interface without making the code more complex. The manual shows how to do it in style: https://protesilaos.com/emacs/modus-themes#h:b6466f51-cb58-4007-9ebe-53a27af655c7.

modus-themes-markup

This was a poorly named user option that only affected inline code elements in prose. The new semantic colour mappings provide more points of entry and thus make it easier to tweak things to one’s liking (including tables, property drawers, source block delimiters (the #+begin_src and #+end_src lines)), and more. The manual shows how: https://protesilaos.com/emacs/modus-themes#h:bb5b396f-5532-4d52-ab13-149ca24854f1.

modus-themes-paren-match

The colouration of matching parentheses of the show-paren-mode can still be affected via overrides: https://protesilaos.com/emacs/modus-themes#h:259cf8f5-48ec-4b13-8a69-5d6387094468.

modus-themes-syntax

This was a user option that controlled the colouration of programming modes. We can reproduce it with overrides, except we now also have the freedom to adapt things further:

modus-themes-links

The colouration of links can now be affected via palette overrides, as documented in the manual: https://protesilaos.com/emacs/modus-themes#h:6c1d1dea-5cbf-4d92-b7bb-570a7a23ffe9.

modus-themes-region

Overrides can be used to affect the region’s colouration and/or to prevent the active region highlight from changing the underlying text colour. As always, the manual covers the details: https://protesilaos.com/emacs/modus-themes#h:c8605d37-66e1-42aa-986e-d7514c3af6fe.

modus-themes-deuteranopia

Instead of this rather limited option, users are advised to use the new bespoke themes: modus-operandi-deuteranopia and modus-vivendi-deuteranopia. They are designed to cater to the needs of people with red-green colour deficiency.

modus-themes-mail-citations

All parts of an email composition buffer (per the standard message.el library) are configurable via palette overrides. Not just citation lines, but also message headers. The manual shows several stylistic alternatives: https://protesilaos.com/emacs/modus-themes#h:7da7a4ad-5d3a-4f11-9796-5a1abed0f0c4.

Note that apart from this change, I also redesigned several faces that affect emails. This was done in the interest of consistency and to avoid some exaggerations.

modus-themes-tabs-accented

I do not provide documentation on how to reproduce this style because I think it was not widely used. It is possible to do it with overrides. If anyone needs it, they are invited to contact me about it.

modus-themes-box-buttons

All “graphical” buttons use a proportionately spaced font (variable-pitch) by default as it helps with legibility. The colours of those buttons can be changed by overriding the relevant entries: https://protesilaos.com/emacs/modus-themes#h:4f6b6ca3-f5bb-4830-8312-baa232305360.

[ Use my fontaine package to affect fonts via faces and to apply presets for various contexts. ]

Changes to remaining user options

The modus-themes-headings also affects the Org agenda

This user option applies to heading level 0 through 8 and also to the agenda date and structure constructs. Here is a complete example:

(setq modus-themes-headings ; read the manual's entry of the doc string
      '((0 . (variable-pitch light 1.9))
        (1 . (variable-pitch light 1.8))
        (2 . (variable-pitch regular 1.7))
        (3 . (variable-pitch regular 1.6))
        (4 . (variable-pitch regular 1.5))
        (5 . (variable-pitch 1.4)) ; absence of weight means `bold'
        (6 . (variable-pitch 1.3))
        (7 . (variable-pitch 1.2))
        (agenda-date . (semilight 1.5))
        (agenda-structure . (variable-pitch light 1.9))
        (t . (variable-pitch 1.1))))

The modus-themes-headings no longer affects colours

All colour-related changes can be done via palette overrides. This gives the user maximum flexibility on the choice of applied colours (e.g. to have alternating contrasting foregrounds or shades of the same hue). The manual shows several examples: https://protesilaos.com/emacs/modus-themes#h:11297984-85ea-4678-abe9-a73aeab4676a.

The modus-themes-completions is simpler

It no longer covers popup entries as distinct from selection. This is because I revised all the applicable colours and faces to consolidate styles.

The matches and selection keys now read the same list of values.

All changes to colours are done through palette overrides, as demonstrated in the manual (again, far more flexible): https://protesilaos.com/emacs/modus-themes#h:d959f789-0517-4636-8780-18123f936f91.

The modus-themes-prompts is simpler

This user option now only affects the typographic features of prompts. It can read any font weight, as explained in its documentation. Colours are influenced by semantic colour mappings in the palette and can be overridden accordingly. The manual shows several styles: https://protesilaos.com/emacs/modus-themes#h:bd75b43a-0bf1-45e7-b8b4-20944ca8b7f8.

Auto-reload theme when configuring via Custom

The user option modus-themes-custom-auto-reload supersedes the old modus-themes-inhibit-reload. It is now set to a non-nil value by default.

We do this as a convenience for users who tweak theme settings via the Custom UI and who do not know that all modifications to user options require a theme re-load for changes to take effect. Read more in the manual: https://protesilaos.com/emacs/modus-themes#h:9001527a-4e2c-43e0-98e8-3ef72d770639.

Deprecation of public functions

The modus-themes-color and modus-themes-color-alts are deprecated. Users are invited to concentrate on the modus-themes-with-colors macro. The manual provides several examples on that front.

The modus-themes-load-themes is no longer necessary due to the refactoring of the code base.

The modus-themes-load-operandi and modus-themes-load-vivendi are superseded by the general modus-themes-load-theme. It accepts the symbol of a Modus theme as its argument.

The command modus-themes-report-bug is no more. Just send an email to the mailing list or to me privately. Find the information with M-x describe-package and then specify modus-themes. Alternatively, check my website: https://protesilaos.com/contact.

Removed support for some packages

These are the most notable packages that are no longer supported:

  • dired+
  • lsp-mode
  • helm
  • treemacs

The reason is that they are very hard to use for me as an outsider. They provide lots of features, which means that I cannot easily identify faces in their context unless I become an expert in the relevant functionality.

Other removed packages:

  • artbollocks-mode. Use writegood-mode.
  • apropos. Its default faces are fine.
  • awesome-tray.
  • bbdb and ebdb. They are hard to set up, but their faces are usable.
  • calfw. Hard to set up and also seems to no longer be maintained.
  • easy-jekyll
  • dir-treeview
  • eros
  • eshell-git-prompt
  • eshell-prompt-extras
  • eshell-syntax-highlighting
  • evil-goggles
  • evil-snipe
  • evil-visual-mark-mode
  • fountain-mode. I need someone who uses it to help me test it.
  • macrostep
  • mentor
  • mini-modeline
  • mmm-mode. I need someone who uses it to help me test it.
  • org-table-sticky-header.
  • phi-grep
  • pomidor
  • rainbow-blocks. Use Adam Porter’s (aka alphapapa) prism.el.
  • semantic
  • smartparens
  • spaceline
  • sx
  • telephone-line
  • tomatinho
  • winum
  • xterm-color.

Thanks for their feedback on the development of version 4

In alphabetical order:

The largest release to date

There are many more changes that I did not describe. This already lengthy document is me covering just the headline features. The gist is that I spent the last month refactoring and testing the themes to ensure they can cope with the needs of users for years to come.

I understand that the palette overrides are a new way of doing things and that some users may be inconvenienced over the short-term as they update their configurations. I strongly believe that this system is better and the Modus themes can now cover all the legibility needs of users, while also catering to their aesthetic preferences.