2006091 - Sidebar text has low contrast with vertical tabs enabled for themes with contrasting frame/toolbar colors

Status: VERIFIED FIXED

(Firefox :: Theme, defect)

Description

[Kestrel]

Attachment: Comparison showing loss of text contrast in sidebar with vertical tabs

STR:

1. Enable vertical tabs on latest Nightly 148.0a1.
2. Install a theme with a dark frame color and light toolbar color with no sidebar colors like Classic System Theme.
3. Open the bookmarks sidebar (Ctrl+B).

Expected:
Sidebar text has good contrast.

Actual:
Sidebar text has poor contrast, black text against dark background.

Does not seem to take into account that vertical tabs causes sidebar to contradict color scheme (Bug 1974988).

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=42ec00e024b6cc3163d702fdcee27721d29085aa&tochange=87cc0511028091ad910e6c71dfdd2d16cb7609f5

Regressed by Bug 1993421.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

:emilio, since you are the author of the regressor, bug 1993421, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Emilio Cobos Álvarez [:emilio]]

Attachment: Bug 2006091 - Only use preferred-color-scheme override explicitly on our browsing context. r=#layout

Otherwise let the embedder propagate the right information, which
matches how the page would render with the system setting without the
override.

Comment 3

[Emilio Cobos Álvarez [:emilio]]

Comment on attachment 9533084 [details]
Bug 2006091 - Only use preferred-color-scheme override explicitly on our browsing context. r=#layout

Beta/Release Uplift Approval Request

• User impact if declined/Reason for urgency: Theming regression (comment 0)
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: comment 0
• List of other uplifts needed: none
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Simple change that is not web exposed.
• String changes made/needed: none
• Is Android affected?: No

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/2ade44471efb
https://hg.mozilla.org/integration/autoland/rev/73e0d696ceb2
Only use preferred-color-scheme override explicitly on our browsing context. r=jwatt

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/99ae537386ee
https://hg.mozilla.org/integration/autoland/rev/1367cdf64f94
Revert "Bug 2006091 - Only use preferred-color-scheme override explicitly on our browsing context. r=jwatt" for causing mochitest failures @ test_emulate_color_scheme.html

Comment 6

[Sandor Molnar[:smolnar]]

Backed out for causing mochitest failures @ test_emulate_color_scheme.html

Backout link: https://hg-edge.mozilla.org/integration/autoland/rev/1367cdf64f94fc58f72bb14e8aa3475497dfb249

Push with failures

Failure log -> TEST-UNEXPECTED-FAIL | layout/base/tests/test_emulate_color_scheme.html | Dark emulation works - got 1, expected 2

Comment 7

[Emilio Cobos Álvarez [:emilio]]

Fixed the test in xorigin mode.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/64841b5dc9c7
https://hg.mozilla.org/integration/autoland/rev/ed2d10c4f992
Only use preferred-color-scheme override explicitly on our browsing context. r=jwatt

Comment 9

[Cristian Tuns]

https://hg.mozilla.org/mozilla-central/rev/ed2d10c4f992

Comment 10

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9533084 [details]
Bug 2006091 - Only use preferred-color-scheme override explicitly on our browsing context. r=#layout

Approved for 147.0b5.

Comment 11

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/31d95a53ffe5
https://hg.mozilla.org/releases/mozilla-beta/rev/25cd691c595c

Comment 12

[Timea Zsoldos [:tzsoldos], Desktop QA]

I have reproduced this issue using Firefox 148.0a1 (2025.12.11) on Windows 11 and Ubuntu 22.
I can confirm this issue is fixed, I verified using latest Nightly Firefox 148.0a1 (2025.12.17) on Windows 11, Ubuntu 22 and macOS 10.15.
I will come back and verify on Firefox 147.0b5 when the build will be available on archive Mozilla.

Comment 13

[Dianna Smith [:diannaS]]

Comment on attachment 9533084 [details]
Bug 2006091 - Only use preferred-color-scheme override explicitly on our browsing context. r=#layout

Approved for 146.0.1 dot release

Comment 14

[Pulsebot]

https://github.com/mozilla-firefox/firefox/commit/ff72bafa1aa0
https://hg.mozilla.org/releases/mozilla-release/rev/86bb7f6af631

Comment 15

[Timea Zsoldos [:tzsoldos], Desktop QA]

Verified as fixed on Firefox 147.0b5 and Firefox 146.0.1 with Windows 11, Ubuntu 22 and macOS 10.15.