GNU ELPA - colorful-mode

• colorful-allow-mouse-clicks (default: t) If non-nil, allow using mouse buttons for change color.
• colorful-use-prefix (default: nil) If non-nil, use prefix for preview color instead highlight them.

⛔ WARNING: CSS-DERIVED MODES COLORIZE RGB AND HEX COLORS OUT THE BOX,
THIS MAY INTERFERE WITH COLORFUL PREFIX, YOU CAN DISABLE THIS SETTING
`css-fontify-colors' TO nil

• colorful-prefix-string (default: "●") String to be used in highlights. Only relevant if `colorful-use-prefix' is non-nil.
• colorful-prefix-alignment (default: 'left) The position to put prefix string. The value can be left or right. Only relevant if `colorful-use-prefix' is non-nil.

• colorful-extra-color-keyword-functions default: '(colorful-add-hex-colors (emacs-lisp-mode . colorful-add-color-names) ((html-mode css-mode) . (colorful-add-css-variables-colors colorful-add-rgb-colors colorful-add-hsl-colors colorful-add-oklab-oklch-colors colorful-add-color-names)) (latex-mode . colorful-add-latex-colors)) List of functions to add extra color keywords to colorful-color-keywords.

  It can be a cons cell specifying the mode (or a list of modes) e.g:

  (((css-mode css-ts-mode) . colorful-add-rgb-colors) (emacs-lisp-mode . (colorful-add-color-names colorful-add-rgb-colors)) ((text-mode html-mode) . (colorful-add-color-names colorful-add-rgb-colors)) …)

  Or a simple list of functions for executing wherever colorful is active: (colorful-add-color-names colorful-add-rgb-colors)

  Available functions are:

  • colorful-add-hex-colors.
  • colorful-add-color-names.
  • colorful-add-css-variables-colors.
  • colorful-add-rgb-colors.
  • colorful-add-hsl-colors.
  • colorful-add-latex-colors
• colorful-exclude-colors (default: '("#define")) List of keywords not to highlight.
• colorful-short-hex-conversions (default: t) If non-nil, colorful will converted long hex colors to \"#RRGGBB\" format. Setting this to non-nil can make converted hex inaccurate.
• colorful-only-strings (default: nil) If non-nil, colorful will only highlight colors inside strings. If set to `only-prog', the colors in `prog-mode' will be highlighted only if they are inside a string, this doesn't include `css-mode' and derived.
• colorful-highlight-in-comments If non-nil, colorful will highlight colors inside comments. NOTE: If this is set, this will highlight any keyword within the comments, including color names, which can be annoying.
• colorful-html-colors-alist Alist of HTML colors. Each entry should have the form (COLOR-NAME . HEXADECIMAL-COLOR).
• global-colorful-modes (default: '(prog-mode help-mode html-mode css-mode latex-mode)) Which major modes global-colorful-mode is switched on in (globally).

• colorful-base Face used as base for highlight color names. Changing background or foreground color will have no effect.

• colorful-change-or-copy-color Change or copy color at point to another format.
• colorful-convert-and-change-color Convert color at point or colors in region to another format.
• colorfu-convert-and-copy-color Convert color at point to another format and copy it to the kill ring.
• colorful-mode Buffer-local minor mode.
• global-colorful-mode Global minor mode.

These key bindings are defined by: colorful-mode-map

• C-x c x → colorful-change-or-copy-color.
• C-x c c → colorful-convert-and-copy-color.
• C-x c r → colorful-convert-and-change-color.

If you want to use css rgb colors outside css-derived modes, you can add them to `colorful-extra-color-keyword-functions' in your config.

(add-to-list 'colorful-extra-color-keyword-functions '(insert-your-major-mode . colorful-add-rgb-colors))

If you want also use hsl and rgb together you can use this

(add-to-list 'colorful-extra-color-keyword-functions '(insert-your-major-mode . (colorful-add-rgb-colors colorful-add-hsl-colors)))

colorful provides extra functions out-the-box that enable additional highlighting:

• colorful-add-hex-colors: Add Hexadecimal colors highlighting.
• colorful-add-color-names: Add color names highlighting.
• colorful-add-css-variables-colors: Add CSS user-defined color variables highlighting.
• colorful-add-rgb-colors: Add CSS RGB colors highlighting.
• colorful-add-oklab-oklch-colors: Add CSS OkLab and OkLch colors highlighting.
• colorful-add-hsl-colors: Add CSS HSL colors highlighting.
• colorful-add-latex-colors: Add LaTeX rgb/RGB/HTML/Grey colors highlighting.

See: colorful-extra-color-keyword-functions for more details.

If you want to disable colorful at region this hack may be useful for you:

(add-hook 'post-command-hook
	  (lambda ()
	    "delete colorful overlay on active mark"
	    (when-let* (colorful-mode
			(beg (use-region-beginning))
			(end (use-region-end)))
	      ;; Remove full colorful overlay instead only the part where
	      ;; the region is.
		  (dolist (ov (overlays-in beg end))
		    (when (overlay-get ov 'colorful--overlay)
		      (delete-overlay ov))))))

(add-hook 'deactivate-mark-hook
	  (lambda ()
	    "refontify deleted mark"
	    (when-let* (colorful-mode
			(beg (region-beginning))
			(end (region-end)))
	      (font-lock-flush beg end))))