Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• This is not a support issue or a question. For support, questions, or help, visit /r/uBlockOrigin.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• uBO uses default lists and settings.
• using a new, unmodified browser profile.

Description

In dark mode, a momentary FOUC white flash occurs when opening and refreshing the Dashboard page, which is very annoying and unfriendly to the eyes.

Adding the following to the dashboard.html page should fix the issue:

<meta name="color-scheme" content="light dark" />
<style>
:root {
	color-scheme: light dark;
	background-color: light-dark(rgb(240, 240, 242), rgb(27, 27, 35));
}
</style>

A specific URL where the issue occurs.

moz-extension://637c5b58-c248-4b59-aaff-17ada4d976c1/dashboard.html#settings.html

Steps to Reproduce

1. Both the system and browser are in dark mode
2. Click toolbar uBlock Origin browser action button (popup)
3. Click Open the dashboard button in the popup
4. The moment you open the dashboard, the white flash will occur
5. Click browser Reload current page button (or Command+R), reproduce again

Expected behavior

No annoying FOUC white flash 🙏

Actual behavior

Have annoying FOUC white flash almost everytime 💥

uBO version

uBlock Origin 1.63.2

Browser name and version

Firefox

Operating System and version

macOS