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

Firefox Awarie witryn
felixbrakel odpowiedziano
felixbrakel
felixbrakel

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

Wszystkie odpowiedzi (2)

jscher2000 - Support Volunteer
jscher2000 - Support Volunteer

Wybrane rozwiązanie

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?