Emacs: ef-themes version 1.5.0

The ef-themes is a collection of light and dark themes for GNU Emacs whose goal is to provide colourful (“pretty”) yet legible options for users who want something with a bit more flair than the modus-themes (also designed by me).

Below are the release notes.

The new ef-arbutus and ef-rosa themes

The ef-arbutus theme combines red and green colours against a mild light red-pink background. The announcement article contains screenshots: https://protesilaos.com/codelog/2023-12-29-ef-arbutus/.

The ef-rosa theme has a deep dark red-brown background with a blend of magenta and green foregrounds. Check the blog post for pictures: https://protesilaos.com/codelog/2024-01-06-emacs-ef-rosa/.

These two new entries bring the total count of the collection to 30.

Remember that you can set the user option ef-themes-to-toggle to two themes in the collection and switch between them with the command ef-themes-toggle. For example:

(setq ef-themes-to-toggle '(ef-arbutus ef-rosa))

Otherwise, use the command ef-themes-load-random (call it with a C-u prefix argument to limit the result to either dark or light themes, else call it from Lisp, like (ef-themes-load-random 'dark)).

Stopped the transient buffers from trying semantic key colouration

In a recent version of transient.el, there is a new user option that applies colour-coding to keys (e.g. we see those while using magit): transient-semantic-coloring. This option is enabled by default, changing the previous style that was used as a reference for all my designs.

The idea with such colour coding is to indicate when a key continues to display the transient, exits with a given action, and the like. For our purposes this interface cannot work:

  • We need some place to teach users what each colour means, as there are no indicators of any sort to help them (whereas, say, in diff buffers we have the plus and minus signs).

  • Not all hues are suitable for highlighting a single character. In light themes, for example, green and yellow colours are TERRIBLE choices for the requirements of this interface where the key must be clearly visible. But when we introduce multiple colours, each with their own meaning, we will not be able to avoid those hues.

  • The style of key bindings is not limited to transient.el. We find them when we invoke M-x, do M-x describe-bindings, while using the which-key package, and many more. If we are to change how transient.el shows key bindings, then we have to retain the same visual cues for other contexts. Otherwise, everything is inconsistent.

  • All themes must use the same colours to preserve the colour coding, thus removing an important aspect of their presentation.

  • This whole paradigm does not work for themes that are optimised for users with colour deficiency, due to the reduced number of suitable hues. With deuteranopia, for example, we can only rely on yellow and blue: since yellow is not optimal for single key highlights against a light backdrop, blue is the only hue that works in such a context.

The ef-themes will not support this user option. All relevant faces use the style of standard key bindings.

Themes can enforce user option values, but I have decided to change the faces instead to better communicate my intent. If a user wants semantic colouring, they can change the faces to whatever they like.

The evil prompts now show the correct colours

While using evil-mode, the ex prompts no longer use their generic hardcoded red value. They take an appropriate colour from the active Ef theme.

The imenu-list package is now supported

This package uses the built-in imenu infrastructure to produce a sidebar with points of interest in the buffer. Those headings now use the correct colour values.

Thanks to newhallroad for bringing this matter to my attention in issue 35 on the GitHub mirror: https://github.com/protesilaos/ef-themes/issues/35.

The nerd-icons-completion package is covered

This package defines a single face for directories/folders. It looks like all the other nerd-icons packages that use that icon, such as nerd-icons-dired.

Thanks to Ryan Kaskel for the contribution: https://lists.sr.ht/~protesilaos/ef-themes/patches/47379. The change is small. Ryan does not need to assign copyright to the Free Software Foundation.

Completed the coverage of the denote faces

The new style ensures better thematic consistency.

These faces are found in Dired buffers when denote-dired-mode is enabled. Same for the default style of the backlinks buffer.

Changed highlights to avoid conflating “flagged” and “trashed” emails

This is for email clients such as mu4e and notmuch. Flagged ad trashed emails used to have the same colour, which was a problem when the user would try to filter in such a way as to show both at the same time.

Thanks to Adam Porter (GitHub user alphapapa) for bringing this matter to my attention in issue 32 on the GitHub mirror: https://github.com/protesilaos/ef-themes/issues/32.

Support for more specialised faces

  • blink-matching-paren-offscreen: Defined in the built-in simple.el to highlight the matching parenthesis in the echo area when it is off screen (Emacs 30).

  • mct-highlight-candidate: Part of the mct package to highlight the currently selected completion candidate in the *Completions* buffer.

  • shr-mark: Used by the built-in shr library (Simple HTML Renderer) to highlight <mark> tags (Emacs 29).

Expanded the semantic colour mappings

Each theme defines colours and then maps them to semantic constructs. The idea is to not hardcode colour values, but to have an indirection that enforces consistency, while keeping things flexible/customisable. Users can override palette entries as explained in the manual: https://protesilaos.com/emacs/ef-themes#h:4b923795-4b23-4345-81e5-d1c108a84b6a.

New semantic colour mappings are:

  • bg-search-current: Background colour of the currently matched term of search interfaces, like isearch.

  • bg-search-lazy: This background is used in the same contexts as the above, but for matches other than the current one.

  • bg-search-replace: Background of the currently targeted replacement in query-replace operations or related.

  • bg-search-rx-group-{0..3},: Backgrounds for regular expression groups, such as while using M-x re-builder.

  • bg-fringe and fg-fringe: Applies to the background of the fringe area in Emacs frames. By default, the Ef themes do not use a distinct background there, so this is for those who need it.

  • prose-table-formula: Used for formula entries in plain text tables, such as with Org, to distinguish them from the other contents of the table.


  • Used the updated modus-themes formula for the contrast tables of all the Ef themes (stored in the file contrast-ratios.org in the project’s root directory).

    I made this change in commit b410fcc in the modus-themes repo. The idea is to avoid the use of the cl-loop and other cl- functions that we don’t really need (and which also have their own mini language that I find hard to remember/use).

  • Tweaked the value of a few accented backgrounds to better fit with each theme’s style. These colours may not be spotted anywhere right now, but are nonetheless available to those who use palette overrides (run the command ef-themes-preview-colors or ef-themes-preview-colors-current to visualise them).