1950510 - macOS menu bar sometimes glitches to wrong text colour if using full screen and dark mode

Status: RESOLVED DUPLICATE of bug 1941595

(Core :: Widget: Cocoa, defect)

Description

[Siguza]

Attachment: Untitled.png

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:135.0) Gecko/20100101 Firefox/135.0

Steps to reproduce:

1. Set your OS theme to dark mode in macOS System Settings > Appearance.
2. Open two Firefox windows.
3. Put one window into full screen, then switch back to the other window.
4. Open a second application (Finder, Calculator, TextEdit, whatever).
5. Keep switching back and forth between the non-fullscreen Firefox window and the other application (can be via clicking the windows, clicking the dock icons, or using cmd+tab) and observe the menu bar at the top of the screen.

Actual results:

Most of the time, the menu bar stays white on dark grey, but every now and then, it changes to black on dark grey (see screenshot).

Tested on macOS 15.3.1 with Firefox 135.0.1 (stable) and 137.0a1 (2025-02-25) (nightly).

Expected results:

The menu bar should never use black text when in dark mode.

Note: I'm not 100% sure whether this is actually a bug in Firefox or in the macOS GUI stack, but my attempts to reproduce this with any other app have so far been unsuccessful.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::Widget: Cocoa' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.