warm-mode.el

A global minor mode that warms Emacs colors for nighttime coding. Reduces blue light and slightly dims colors across all faces, working with any theme.

Why

System-wide tools like wlsunset apply a blue light filter to your entire screen. warm-mode is useful when you only want the effect in Emacs, leaving other applications unaffected. It also works cross-platform, unlike most system-wide tools. You could also combine both for extra warmth.

Another alternative is to switch to a different theme at night, but warm-mode preserves your exact color scheme, just making it warmer. This makes it easier to adapt without losing familiarity with your theme.

Screenshots

Examples using warm-mode-warmth 0.25 and warm-mode-dim 0.9.

modus-vivendi

Disabled	Enabled

modus-operandi

Disabled	Enabled

creamy

Disabled	Enabled

Installation

Using use-package:

(use-package warm-mode
  :ensure (:host github :repo "smallwat3r/emacs-warm-mode"))

Or manually, clone this repository and add to your load-path:

(add-to-list 'load-path "/path/to/emacs-warm-mode")
(require 'warm-mode)

Usage

Toggle warm mode:

M-x warm-mode

Customization

Variable	Default	Description
warm-mode-warmth	0.2	Intensity of warm shift (0.0 to 0.5)
warm-mode-dim	0.9	Brightness multiplier (0.5 to 1.0)

Example configuration:

(use-package warm-mode
  :ensure (:host github :repo "smallwat3r/emacs-warm-mode")
  :custom
  (warm-mode-warmth 0.25)
  (warm-mode-dim 0.9))

Limitations

1. Only foreground and background colors are transformed. Attributes like :underline or :box usually inherit from foreground, so they are effectively warmed. However, if a theme explicitly sets a color for these attributes, that color will not be transformed.

2. The mode is global and cannot be enabled per-frame.

3. The warming algorithm is simple and not a proper color temperature shift like f.lux or Redshift. Results may vary depending on your theme.

4. May not change text colors in terminal Emacs where color support is limited.