In "Language and Appearance" Dark theme is selected. Also in "Themes" the dark theme is selected. Some websites are displayed in light colours, despite this, which is an annoyance, but not yet a problem. The problem is the "light" websites are displayed in pink-ish palette, which seems to correspond to the default light theme. browser.display.background_color is set to #FFFFFF, so no pink here. privacy.resistFingerprinting, which should have no impact, but one help article suggest that it might interfere is set to false The problem appeared after the last restart, which may also mean the last update. Any ideas how I can make either the dark theme work properly or at least have the webpages displayed in their original colours rather then pink hue?