Firefox Options and add-ons manager still appear white in Firefox browser when the dark mode is enabled, Mozilla has introduced a new pref, which when enabled, makes them look completely dark.
Firefox already supports dark mode and respects Windows 10 theme settings (but do know, built-in themes doesn’t honor accent color setting for title bars). Apparently, the company has added a new pref to Firefox Nightly to make in-content preferences and about:addons to go black, here is how you can enable that preference.
Enable dark mode for Firefox options and add-ons manager in Windows 10
1. Ensure you’re using Firefox 68 Nightly
2. Visit about:config
3. Find and toggle browser.to “true”.
4. Restart the browser, open about:addons and about:preferences in new tabs and leave Firefox open aside
5. In Windows 10, click on Start > Settings > Personalization
6. Colors > Dark mode
Now switch to options and add-ons manager tabs in Firefox to notice the change.
