Until the update to 89.0 Firefox used to display the Windows 10 "Accent Color" (Settings => Personalization => Choose your accent color) on the title / tab bar when the browser was the active windows. With 89.0 it's always grey, whether active or inactive. Is there a way to restore the old behavior? I've found some suggestions using CSS and a file named userChrome.css, but these do not seem to work...