We're calling on all EU-based Mozillians with iOS or iPadOS devices to help us monitor Apple’s new browser choice screens. Join the effort to hold Big Tech to account!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Avatar for Username

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Hierdie gesprek is in die argief. Vra asseblief 'n nuwe vraag as jy hulp nodig het.

'prefers-color-scheme' media query returns 'light' no matter what

  • 2 antwoorde
  • 0 hierdie probleem
  • 4 views
  • Laaste antwoord deur felixbrakel

felixbrakel
felixbrakel
more options

I noticed this first when I had to force Google to go into dark mode even though firefox was already in dark mode.

I have searched through some issue reports and have seen a lot of people mentioning that their system theme is not being detected properly. This is not that issue. I can set the firefox "Website appearance" to dark or automatic at which point the UI of firefox itself does do into dark mode so no issues there. However if I go to a website that tries to query 'prefers-color-scheme' and set its theme accordingly it always returns 'light'. This is the case even if I set the 'layout.css.prefers-color-scheme.content-override' to 0 in about:config.

I used this website to test: https://septatrix.github.io/prefers-color-scheme-test/

The issue persists when opening a website in a private window.

Let me know if I need to provide additional information.

-Felix

I noticed this first when I had to force Google to go into dark mode even though firefox was already in dark mode. I have searched through some issue reports and have seen a lot of people mentioning that their system theme is not being detected properly. This is not that issue. I can set the firefox "Website appearance" to dark or automatic at which point the UI of firefox itself does do into dark mode so no issues there. However if I go to a website that tries to query 'prefers-color-scheme' and set its theme accordingly it always returns 'light'. This is the case even if I set the 'layout.css.prefers-color-scheme.content-override' to 0 in about:config. I used this website to test: https://septatrix.github.io/prefers-color-scheme-test/ The issue persists when opening a website in a private window. Let me know if I need to provide additional information. -Felix

Gekose oplossing

Setting "layout.css.prefers-color-scheme.content-override" to 0 is the same as selecting Dark for Website Appearance (Change website appearance settings in Firefox).

I am aware of one setting that will causes "prefers-color-scheme" to unfailingly return light, and that is setting "privacy.resistFingerprinting" to true in about:config. Does that ring a bell?

Lees dié antwoord in konteks 👍 0

All Replies (2)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer
  • Top 10 Contributor
more options

Gekose oplossing

Setting "layout.css.prefers-color-scheme.content-override" to 0 is the same as selecting Dark for Website Appearance (Change website appearance settings in Firefox).

I am aware of one setting that will causes "prefers-color-scheme" to unfailingly return light, and that is setting "privacy.resistFingerprinting" to true in about:config. Does that ring a bell?

felixbrakel
felixbrakel Vraag-eienaar
more options

Yep, that was it