Hi, This thread https://support.mozilla.org/en-US/questions/1538723 This is for high contrast theme users such as the greyeve theme (universal windows 10 darkmode theme) Which is the top google result for "thunderbird high contrast override" Has been locked and so I cannot post this reply. Since that thread does not contain a valid usable answer Anyone coming in from google search, here is the answer Go to general -> config editor and set the following value to 1 browser.display.document_color_use = 1