311727 2026-04-08 06:17:08 -0700 Implement `color_scheme_dark` manifest member 2026-04-10 07:13:32 -0700 1 1 1 Unclassified WebKit WebKit Misc. WebKit Nightly Build Unspecified Unspecified NEW InRadar P2 Normal --- 1 marcosc hi dmurph webkit-bug-importer oldest_to_newest 2197961 0 marcosc 2026-04-08 06:17:08 -0700 The Web App Manifest spec (w3c/manifest PR #1207) adds a `color_scheme_dark` member that allows web apps to specify alternative `theme_color` and `background_color` values for dark-mode operating system themes. **Spec PR:** https://github.com/w3c/manifest/pull/1207 **Closes manifest issue:** https://github.com/w3c/manifest/issues/975 ## What to implement `color_scheme_dark` is an ordered map whose keys are "themeable members" (`theme_color`, `background_color`) and whose values are CSS color strings. When applying a manifest and the OS uses a dark color theme, for each themeable member that exists in `color_scheme_dark`, the UA SHOULD use the dark value in place of the base value, unless user accessibility preferences take precedence. **Example manifest:** ```json { "background_color": "#fff", "theme_color": "red", "color_scheme_dark": { "background_color": "#000", "theme_color": "hotpink" } } ``` ## Implementation notes - Parse `color_scheme_dark` as an ordered map during manifest processing (see `process the color_scheme_dark member` algorithm in the spec) - Iterate over the fixed list « "theme_color", "background_color" » (not arbitrary keys) - Use the dark values when the system is in dark appearance (UIUserInterfaceStyleDark / NSAppearance.currentAppearance) - Existing `theme_color` and `background_color` behavior is unchanged when `color_scheme_dark` is absent or the system is in light mode ## Status Spec PR is open; waiting for at least one implementation commitment before merging. This bug is the WebKit commitment. 2197962 1 webkit-bug-importer 2026-04-08 06:17:14 -0700 <rdar://problem/174315709> 2198410 2 dmurph 2026-04-09 10:09:31 -0700 Hello! Chromium intends on supporting this as well, this is our implementation tracking bug: https://crbug.com/383165202 Dan 2198785 3 hi 2026-04-10 07:13:32 -0700 Pull request: https://github.com/WebKit/WebKit/pull/62443