I can't see blue text on a black background as well. Did you make changes to the default colors? You can check the default color settings to see if the text color is still white *Options/Preferences -> General: Fonts & Colors -> Colors: See also: *"Override the colors specified by the page with my selections above" Try "Never" if the default "Only with High Contrast themes" isn't working properly. ---- *https://support.mozilla.org/en-US/kb/change-fonts-and-colors-websites-use *https://support.mozilla.org/en-US/kb/firefox-options-preferences-and-settings