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Emacs: modus-themes version 4.2.0

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 soon install the changes in emacs.git so please wait a little longer for the updates to trickle down to you.

I won a Google award for the Modus themes

Report here: https://protesilaos.com/codelog/2023-05-25-emacs-google-award/.

This is not a “change” per se, but it is worth documenting here. It shows how important accessibility can be in empowering people to use their computer and, in our case, to exercise their software freedoms.

The Modus themes tend to one aspect of accessibility. They do not exhaust the topic, though they should at least raise awareness about the significance of tending to the usability needs of everyone. The effort I put into documenting the themes (and my other packages) should be understood in this light as a means of helping people enjoy their software freedom by learning how to use and extend the program in question.

New tritanopia-optimised themes

I have created a pair of light and dark themes that are intended for people with blue-yellow colour deficiency (tritanopia). These are modus-operandi-tritanopia (light) and modus-vivendi-tritanopia (dark). Screenshots of all the Modus themes are available on my website: https://protesilaos.com/emacs/modus-themes-pictures.

The entire collection is now described in the manual as follows:

The Modus themes consist of eight themes, divided into four 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).

  • Tritanopia themes: modus-operandi-tritanopia and its counterpart modus-vivendi-tritanopia are optimized for users with blue-yellow color deficiency. The idea is the same as with the deuteranopia variants: color coding relies only on hues that are accessible to people with tritanopia or tritanomaly, namely, shades of red and cyan.

Recalibrated the “graph” colours in all themes

The new palette subset improves the contrast of all the relevant colours when presented side-by-side. These are most notably used by the org-habit consistency graph, which is displayed in the Org agenda. The deuteranopia and tritanopia themes have their own bespoke colours for this purpose, due to their specific requirements for colour coding (e.g. they cannot use green).

Faces or face groups

  • Introduced a subtle 3D effect for clickable buttons, replacing the previous 2D design. I realised the flat style creates ambiguity between the button and the text fields. This happens, for example, with M-x customize-variable for org-capture-templates which has lots of button and text field combinations. The added sense of depth helps with the usability of these buttons because it makes them unambiguous. Personally, I prefer the 2D approach, but here we have a trade-off between usability and aesthetics. According to what I state in the manual:

    If there arises an inescapable trade-off between usability and stylistic considerations, we will always opt for the former.

  • Refashioned the whitespace-mode to be much more subtle and added the concomitant semantic colour mappings.

    The previous style involved the use of a dim grey background for each invisible character. While this is was good to spot invisible characters quickly, it was a major hindrance for users who want to run whitespace-mode at all times (e.g. for the Python programming language which is space-sensitive).

    We thus remove the backgrounds by default but provide the option to reinstate them via palette overrides (as documented at length in the manual). To this end, we have two new semantic colour mappings for ordinary space, its invisible characters, as well as space errors.

    Thanks to Christian Tietze and Oliver Epper for their feedback in issue 80 on the GitHub mirror: https://github.com/protesilaos/modus-themes/issues/80.

  • Applied a more subtle background for faces menu-bar-mode, tool-bar-mode, scroll-bar-mode. They do not need to stand out so much because the toolkit already takes care of that. Also, we do not want to dillute the semantic value of either bg-tab-bar or fringe palette colour mappings that I was wrongly using before in this context. Note that those faces may not apply, depending on the underlying tool kit. For example, I encounter them with the Lucid build of Emacs, though not with the GTK one.

  • Fix the critical typo of ‘widget-buton’, which prevented the actual widget-button face from being affected by the themes. Thanks to Steve Downey for pointing it out in issue 73 on the GitHub mirror: https://github.com/protesilaos/modus-themes/issues/73.

  • Added support for the disk-usage package. It is made to look like Dired, to the extent possible. Thanks to Nacho Barrientos for the patch: https://lists.sr.ht/~protesilaos/modus-themes/patches/39822. The change is small and does not require copyright assignment to the Free Software Foundation.

  • Made the eglot-diagnostic-tag-unnecessary-face look like a warning. By default it inherits the shadow face, which makes it counter-intuitive as it dims the text instead of bringing it to our attention. The intent of eglot-diagnostic-tag-unnecessary-face is to highlight unused symbols, so this is better presented as a warning.

    Thanks to Augusto Stoffel for bringing this matter to my attention. This was done via a private channel and the information is shared with permission.

  • Changed the smerge-markers to inherit from diff-header instead of diff-heading. Thanks to Steve Downey for the contribution. This was done in pull request 74 on the GitHub mirror: https://github.com/protesilaos/modus-themes/pull/74. The change is small and does not require copyright assignment to the Free Software Foundation.

  • Added support for the jinx package. This was originally done by Tomasz Hołubowicz in pull request 71 on the GitHub mirror: https://github.com/protesilaos/modus-themes/pull/71. The change is small and does not require copyright assignment to the Free Software Foundation. I then modified it to make the underlines look like warnings instead of errors. This is because of how the package works: it automatically highlights misspellings in the visible portion of the buffer. There are cases where this results in a very intense presentation, which can be distracting. We want to reduce the overall intensity and not draw too much attention to those highlights.

  • Extended coverage of Org to the new org-agenda-calendar-daterange face (part of Org version 9.7). Thanks to Gautier Ponsinet for the patch, which I received via a private channel. The change is small and does not require copyright assignment to the Free Software Foundation. In addition to this, I introduced a new semantic colour mapping in the themes’ palette called date-range. This can be used with the palette overrides, which are documented at length in the manual (there are lots of copy-pastable examples as well).

  • Supported all of the new faces of the built-in proced package. These are part of Emacs 29 and make the proced buffers more colourful, subject to the user option proced-enable-color-flag. As always, the themes strive to avoid exaggerations, meaning that I apply colour with restraint: not all faces need to stand out.

  • Included the rst-mode in the list of explicitly supported packages, making its heading look like those of Org, Markdown, etc. Thanks to David Edmondson for the patch: https://lists.sr.ht/~protesilaos/modus-themes/patches/40625. I believe David has already assigned copyright to the Free Software Foundation, though this patch is small anyway.

  • Covered all the new faces of the built-in flymake package. These concern the inline feedback messages (Emacs 30) as well as those that appear in the echo area (Emacs 29). The former are subject to the user option flymake-show-diagnostics-at-end-of-line.

  • Reduced the intensity of the which-key prefix descriptions. Those are the keymaps that displayed by which-key to hint that typing the given key will open a new which-key page with more keys.

  • Configured new vundo-saved and vundo-last-saved faces of the vundo package. They are designed to be easy to read, without going over-the-top. Thanks to Nicolas Semrau for bringing this matter to my attention in issue 79 on the GitHub mirror: https://github.com/protesilaos/modus-themes/issues/79.

  • Removed the deprecated consult-preview-cursor face and made the requisite adjustments to the consult faces. This was done in commit 267b0c9 of the Consult Git repository. Discussed here: https://github.com/minad/consult/issues/764#issuecomment-1537491625.

  • Instructed the shr-selected-link face of the built-in shr package to use a “mark selection” style instead of the semantically incorrect “intense red” it had before. This change is helpful for those who override the palette of their Modus theme of choice, while it also allows us to have varied colours depending on the requirements of each theme (e.g. deuteranopia/tritanopia compared to the defaults).

  • Did the same as above, mutatis mutandis, for the faces transient-disabled-suffix, web-mode-error-face, erc-dangerous-host-face, aw-minibuffer-leading-char-face, binder-sidebar-highlight, binder-sidebar-missing, image-dired-thumb-flagged, image-dired-thumb-mark, info-menu-star, rainbow-delimiters-mismatched-face, evil-ex-substitute-matches, iedit-occurrence, iedit-read-only-occurrence, pgtk-im-0, dired-narrow-blink.

  • Enhanced the image-dired mark faces with a box border, as the use of a background alone can be obscured by the underlying image thumbnail, depending on its figures/colours.

  • Removed the backgrounds from the powerline-evil faces and simplified their overral presentation in the interest of maintainability. The old styles were hard to predict and test. There could easily be conflicts, such as if the user would override the colours of the mode line.

  • Ensured that diary and holiday colours are distinct and legible, without being too intense.

Changes to the manual or other documentation

  • Updated the doc string of the primary customisation group defined by the themes to reflect the support for the case of tritanopia.

  • Included links to the web page of the manual and the one with the sample pictures in the customisation groups. Those links appear in the various Custom UI buffers.

  • Introduced an annotation function for all commands that involve minibuffer completion. The annotations display the one-line description of each theme, making it easier for a user to pick their preferred choice (e.g. when using the modus-themes-select command).

  • Defined semantic colour mappings for “marks”. These are used by dired, trashed, proced, and others. These is no change to the default appearance of what users are already familiar with, though it is now possible to override those styles.

  • Complemented the subset of semantic colour mappings for errors/warnings with “prominent” variants. Those employ a background and foreground combination. They are used in all sorts of contexts, such as for fringe errors (flymake, flycheck, …), query-replace, isearch-fail, and others.

  • Wrote sample code on how to add “padding” to the Emacs frame and the space between the Emacs windows. This makes for a presentation that some users find easier to work with.

  • Corrected the sample code for git-gutter to use the appropriate symbols from the theme palette. Thanks to Christian Tietze for the patch: https://lists.sr.ht/~protesilaos/modus-themes/patches/40354. The change is small and does not require copyright assignment to the Free Software Foundation.

  • Removed moody from the list of packages explicitly supported by the themes. We stopped supporting it since version 4 that removed the relevant user option for the mode line. The idea is that the mode line is better handled by the user without interference from the theme, due to the number of options available (and how brittle those can be when interacting with unpredictable face definitions). Thanks to Nicolas De Jaeghere for reminding me to remove moody from the manual: https://lists.sr.ht/~protesilaos/modus-themes/%3Cypi9jzyclqxy.fsf%40gmail.com%3E#%3C87jzybdgg1.fsf@dejaeghe.re%3E.


  • Added two new preset palette overrides to make the overall presentation “warmer” or “cooler”. Those are called modus-themes-preset-overrides-warmer and modus-themes-preset-overrides-cooler, respectively. The manual explains how those presets can be used. I suggest the user does not add such overrides if they intend to load any of the deuteranopia or tritanopia themes, due to the specific requirements of their design.

  • Refined the deuteranopia yellows for warnings, errors, and comments. These otherwise slight adjustments make it considerably easier to tell apart distinct elements that may be positioned close together.

  • Tweaked the deuteranopia semantic colour mappings for emails. The subject line use a more appropriate colour value, while level 3 quotes stand out a bit more than they did before, without being needlessly intense.

  • Arranged for the modus-themes-load-theme function return the value of the THEME argument it accepts. The intent is to allow other functions that call this one to capture the return value for their purposes (such as with a let binding). Thank to Oliver Epper for the feedback in issue 78 on the GitHub mirror: https://github.com/protesilaos/modus-themes/issues/78.