Auto Dark Mode for FreeCAD

Automatically switch FreeCAD themes based on your system's light/dark appearance setting.

Installation

1. Open Preferences... > Addon Manager
2. Add an item in Custom Repositories :

   Repository URL	Branch name
   https://github.com/ndesgranges/freecad-auto-dark-mode	master

3. Press OK and open Tools > Addon Manager
4. Search for freecad-auto-dark-mode and click install
5. Reboot when asked.

You can now configure your themes, see Configuration

Configuration

1. Open FreeCAD
2. Go to Edit > Auto Dark Mode Settings...
3. Configure your preferences:
   • Enable automatic theme switching: Toggle the feature on/off
   • Light mode theme: Select the theme to use when system is in light mode
   • Dark mode theme: Select the theme to use when system is in dark mode
   • Check interval: How often to check for system theme changes
4. Click OK to save

Supported Platforms

Note

Should work for the 3 listed platforms but only tested on MacOS.

macOS

Detects the system appearance setting (System Settings → Appearance).

Windows

Reads the Windows personalization settings from the registry.

Linux

Supports multiple desktop environments:

• GNOME: Reads color-scheme and gtk-theme settings
• KDE Plasma: Reads the color scheme configuration
• Other environments may work if they follow similar conventions

Troubleshooting

Addon not loading

• Check the FreeCAD Report view (View → Panels → Report view) for error messages

Theme not changing

• Ensure automatic theme switching is enabled in settings
• Check the Report view for any error messages
• Verify that the selected themes exist in your FreeCAD installation

Themes not showing in list

• The addon searches for .qss files in:
  • FreeCAD's built-in Gui/Stylesheets folder
  • Theme addons in your Mod folder (FreeCAD-themes, OpenTheme, etc.)
• Check that your theme addons are properly installed

System theme not detected correctly

• On Linux, make sure you have gsettings (GNOME) or kreadconfig5 (KDE)
• The addon checks theme every few seconds; changes may take a moment to apply. See Configuration

License

MIT License - see LICENSE file for details.

Contributing

Contributions are welcome! Please feel free to submit issues and pull requests.