Hello, I have a visual impairment whereby I am very sensitive to light and various colours especially when using a computer monitor. White backgrounds, even at dim brightness levels, cause me severe discomfort and stop me from being able to read text without headaches and migraines. (I have a BenQ flicker free monitor - so backlight flicker is not the problem) The Firefox Config, Options and Add-ons screens all have a blinding white background. I used to use the really useful Blank Your Monitor add-on to override the colours for these pages. Since Mozilla decided to stop add-ons from modifying user interface elements of the Firefox browser since v 57+, I have had an extraordinary amount of trouble with using Firefox comfortably. To help with my disability, I need to set the background for these pages to black and the font to light green. As such, please could someone give me an indication of what CSS code I need to add into the User Chrome CSS to set the background colours of the Options, Config and Add-ons pages to these colours? (for all three pages please) I am aware that in the Colour options (under Options, General, Language and Appearance, Fonts and Colours) I can set colours to override *everything* *always* - but that approach leads to other Add-Ons not working and leads to an unsatisfactory appearance for web pages. The most common sense approach would have been for Mozilla for Firefox 57 (and up) to enable users to enable certain priviledges to certain accessibility add-ons to have deeper abilities (like being able to modify the UI) - but unfortunately that didn't happen. So the only alternative for me is to fiddle with the User Chrome CSS. So if someone could help me out with the CSS I need to do the above I would be really greatful. Thanks in advance :) Glen