In web app scoping for `accent-color: auto` using system accent colors

[kyerebo]

Specification title

CSS Basic User interface Module Level 4

Specification or proposal URL (if available)

https://drafts.csswg.org/css-ui-4/#widget-accent

Explainer URL (if available)

No response

Proposal author(s)

No response

MDN URL

No response

Caniuse.com URL

No response

Bugzilla URL

No response

Mozillians who can provide input

No response

WebKit standards-position

WebKit/standards-positions#613

Other information

Chromium is intending to scope the exposure of system accent color through accent-color: auto on form controls to only be available in installed web apps. This is largely to match the privacy direction already planned for the AccentColor/AccentColorText keywords, which carry significant fingerprinting risk when exposed broadly, and ensure system accent color availability is consistent for developers.

[emilio]

Is there any media query that an app can use to detect if they are installed? display-mode perhaps? If not, should we maybe add one, or one of the @supports keywords?

But this seems reasonable to me over all.

[kyerebo]

Yes, the supported way is to detect standalone matching display-mode.

[marcoscaceres]

"standalone" doesn't quite capture it... in the WebApps WG, there's a proposal to add an installed media feature:
w3c/manifest#1092 (comment)

[kyerebo]

Thanks for letting us know about the installed CSS media feature, I wasn't aware that was being explored. Currently in Chromium we have a reliable way of confirming the install state, so I don't think installed implementation would be a blocker for this scoping position in particular. We're open to separately implementing that installed proposal once it gets off its feet.