SOGo Dark Theme Selector

A custom theme loader and theme selector for SOGo Webmail, designed for Mailcow/SOGo installations.

This project adds a native-looking theme button to the SOGo top toolbar and allows users to switch between the built-in SOGo theme and custom dark themes.

Features

• Theme selector button in the SOGo toolbar
• System theme mode
• Automatic dark mode when the browser prefers dark mode
• Automatic original theme when the browser prefers light mode
• Manual theme override per user
• Persistent user preference via localStorage
• No SOGo source-code modification required
• Separate theme files for easier maintenance
• Works with Mailcow SOGo container mounts

Available Themes

Theme	Description
System	Uses browser preference. Light mode loads original SOGo, dark mode loads Full Dark
Original	Removes custom styling and uses the built-in SOGo theme
Dark Classic	Dark SOGo interface with white mail preview/editor
Dark Full	Fully dark SOGo interface, including mail preview and editor

File Structure

data/conf/sogo/
├── custom-theme.js
└── themes/
    ├── dark-classic-theme.js
    └── dark-full-theme.js

Installation

Mount the custom theme loader and theme directory into the SOGo container.

Example Mailcow compose volume entries:

volumes:
  - ./data/conf/sogo/custom-theme.js:/usr/local/lib/GNUstep/SOGo/WebServerResources/js/theme.js
  - ./data/conf/sogo/themes:/usr/local/lib/GNUstep/SOGo/WebServerResources/js/themes

After placing the files, restart the SOGo container:

docker compose restart sogo-mailcow