*Contact emails*
[email protected]

*Explainer*
*N/A*

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

*Summary*
Currently, if the *accent-color* property for form controls is set to *auto*, 
they adopt the system accent color set by the user in their operating 
system. This happens in all contexts whether on the web or in an installed 
web application. Current feature state: 
https://chromestatus.com/feature/6548224737017856
*AccentColor* and *AccentColorText* CSS keywords, which also adopt the 
system accent color, pose a significant fingerprinting vector if exposed 
widely on the web. As such, they're currently planned to only be available 
in installed web app contexts. We want system accent color exposure to 
match across all vectors, so we should scope *accent-color: auto* to only 
be available in installed web app contexts as well. This introduces more 
consistent developer and user expectations for system colors and aligns 
with fingerprinting restrictions for *AccentColor[Text]*.

*Blink component*
Blink>CSS 
<https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3ECSS%22>

*Web Feature ID*
accent-color <https://webstatus.dev/features/accent-color>

*Motivation*
Currently, system accent color features have differing scopes of 
availability. While *AccentColor[Text]* is planned to only be available in 
installed web apps, *accent-color: auto* uses system accent color 
everywhere. This leads to confusing signaling on when developers can expect 
system accent colors to be available, as well as unintended accessibility 
and UX side effects as form controls adopt colors on web sites that 
developers didn't expect. Scoping system accent color availability to 
installed web apps all up will provide more consistency in this feature 
intended to allow more native app like styling, while adhering to the 
fingerprinting restrictions that *AccentColor[Text]* is planned to be 
subject to (must not be exposed outside of installed web apps).

*Initial public proposal*
*No information provided*

*Search tags*
accent-color <https://chromestatus.com/features#tags:accent-color>, accent 
<https://chromestatus.com/features#tags:accent>, color 
<https://chromestatus.com/features#tags:color>, system accent color 
<https://chromestatus.com/features#tags:system%20accent%20color>

*TAG review*
This is a modification/fix for an existing approved feature.

*TAG review status*
Not applicable

*Risks*


*Interoperability and Compatibility*
There is potential interoperability risk as WebKit exposes the system 
accent color completely un-scoped, while Firefox does not. Conversation 
around fingerprinting mitigation for *AccentColor*, which mentions how it 
should not have differing availability from accent-color: auto: 
https://github.com/w3c/csswg-drafts/issues/10372

*Gecko*: Positive (
https://github.com/mozilla/standards-positions/issues/1354) Emilio noted in 
the attached link that he sees no issues with this.

*WebKit*: No signal (
https://github.com/WebKit/standards-positions/issues/613) In discussion.

*Web developers*: No signals

*Other signals*:

*WebView application risks*

Does this intent deprecate or change behavior of existing APIs, such that 
it has potentially high risk for Android WebView-based applications?
No, but implementing Finch feature flag just in case.


*Debuggability*
No additional functionality needed to debug this feature.

*Will this feature be supported on all six Blink platforms (Windows, Mac, 
Linux, ChromeOS, Android, and Android WebView)?*
No
This is scoping an existing feature, which is currently being supported on 
Windows, Mac, Linux, and ChromeOS. Future support for Android is planned.

*Is this feature fully tested by web-platform-tests 
<https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?*
No
There are no specific tests for this scoping fix. The underlying feature 
relies on the platform's accent color and necessitates a WebDriver 
extension to simulate the accent-color property accurately, making it 
difficult to test. However current WPT coverage for the underlying feature 
was not broken by this change. 
WPT tests listed for underlying feature: 
- https://wpt.fyi/results/css/css-ui/accent-color-parsing.html 
- 
https://wpt.fyi/results/css/css-typed-om/the-stylepropertymap/properties/accent-color.html
 
- 
https://wpt.fyi/results/css/css-ui/animation/accent-color-interpolation.html

*Flag name on about://flags*
*N/A*

*Finch feature name*

*WebAppScopeSystemAccentColor*
*Rollout plan*
Will ship enabled for all users

*Requires code in //chrome?*
False

*Tracking bug*
https://issues.chromium.org/issues/481353056

*Estimated milestones*

Shipping on desktop
147

*Anticipated spec changes*

Open questions about a feature may be a source of future web compat or 
interop issues. Please list open issues (e.g. links to known github issues 
in the project for the feature specification) whose resolution may 
introduce web compat/interop risk (e.g., changing to naming or structure of 
the API in a non-backward-compatible way).
The fingerprinting mitigation for AccentColor and AccentColorText do not 
have widely agreed upon resolution: 
https://github.com/w3c/csswg-drafts/issues/10372 Depending on the results 
of that conversation, it's possible we might be able to un-scope this 
feature in the future.

*Link to entry on the Chrome Platform Status*
https://chromestatus.com/feature/5106043975761920?gate=4678080817922048

This intent message was generated by Chrome Platform Status 
<https://chromestatus.com/>.

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