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

What FF setting triggers dark mode on websites?

  • 1 ŋuɖoɖo
  • 1 masɔmasɔ sia le esi
  • 25 views
  • Nuɖoɖo mlɔetɔ BWPanda

more options

I have two FF profiles. When I open a private window in each profile and go to YouTube, one displays YT in light mode, while the other displays it in dark mode. In both windows, YT is set to ‘Appearance: Device theme’. Both profiles use FF’s ‘Dark’ theme. The same happens when I go to other websites that utilise ’ prefers-color-scheme’ (e.g. https://dashboard.tugboat.qa).

Since these two profiles display websites in different colour schemes on the same computer, it’s clearly not an OS setting. It therefore must be a setting in FF - one that’s enabled in one profile but disabled in the other. I’d like to know what it is.

I’ve tried comparing about:config in both profiles, searching for things like ‘dark’, ‘theme’, ‘color’, etc. But I can find no differences. Can anyone shed some light (pun intended) on this for me?

I have two FF profiles. When I open a private window in each profile and go to YouTube, one displays YT in light mode, while the other displays it in dark mode. In both windows, YT is set to ‘Appearance: Device theme’. Both profiles use FF’s ‘Dark’ theme. The same happens when I go to other websites that utilise ’ prefers-color-scheme’ (e.g. https://dashboard.tugboat.qa). Since these two profiles display websites in different colour schemes on the same computer, it’s clearly not an OS setting. It therefore must be a setting in FF - one that’s enabled in one profile but disabled in the other. I’d like to know what it is. I’ve tried comparing about:config in both profiles, searching for things like ‘dark’, ‘theme’, ‘color’, etc. But I can find no differences. Can anyone shed some light (pun intended) on this for me?
Screen ƒe photowo kpe ɖe eŋu

Ŋuɖoɖo si wotia

I finally worked this out. It's the result of setting 'privacy.resistFingerprinting' to TRUE on the profile that was showing in light mode. With this set back to the default setting of FALSE, websites now show in dark mode.

Xle ŋuɖoɖo sia le goya me 👍 0

All Replies (1)

more options

Ɖɔɖɔɖo si wotia

I finally worked this out. It's the result of setting 'privacy.resistFingerprinting' to TRUE on the profile that was showing in light mode. With this set back to the default setting of FALSE, websites now show in dark mode.