Light & dark themes
Parch ships light and dark themes based on the same token set. The system theme is the single source of truth for applications.
Rules
- Follow the system by default. Read the desktop's color-scheme preference; never ship a theme picker that fights the system setting.
- Both themes come from the same semantic tokens, if you wrote a hex value, you wrote a bug.
- Offer an in-app override only for long-focus surfaces (video players, terminals) and remember it per-app.
- Test both themes on every screen; the design-system demos include a per-demo theme switch to make this routine.
- Images and diagrams need dark variants or a translucent backing surface.
How the system decides
| Environment | Preference source |
|---|---|
| KDE Plasma | Colors & Themes → dark/light style (kdeglobals ColorScheme) |
| GNOME | Appearance → Style (org.gnome.desktop.interface color-scheme) |
| Terminal/web | NO_COLOR respected where applicable; portal: manual toggle |
Applications should never scrape theme files directly; go through the toolkit's theme API so user overrides and third-party themes keep working.