1964563 - White flashes with Light theme and "Dark" website appearance

Status: NEW

(Firefox :: Theme, defect, P3)

Description

[08xjcec48]

Steps to reproduce:

• Select the default Light theme
• Change your website appearance settings to Dark
• Open a website that offers a dark theme, e.g. https://discord.com/
• Use the address bar to navigate to another website that offers a dark theme, e.g. https://bugzilla.mozilla.org/

Actual results:

The New Tab background color (white) causes unwanted flashes between dark websites.

Expected results:

Changing your website appearance settings to Dark should show a dark color while loading websites, regardless of what theme you use.

Comment 1

[08xjcec48]

Comment 2

[Negritas Sergiu, Desktop QA]

Hello! I have managed to reproduce the issue with firefox 140.0a1(2025-05-07) on Ubuntu 22.04.

I will mark this issue as NEW in order to get our developers involved and provide a solution in future releases.

Have a nice day!

Comment 3

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

The severity field is not set for this bug.
:cmkm, could you have a look please?

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