Can you attach a screenshot? *https://support.mozilla.org/en-US/kb/how-do-i-create-screenshot-my-problem *use a compressed image type like PNG or JPG to save the screenshot ---- Make sure you haven't enabled a High Contrast theme in the Windows/Mac Accessibility settings. Make sure you allow pages to choose their own colors as this affects background images. *Options/Preferences -> General: Fonts & Colors -> Colors: "Override the colors specified by the page with my selections above" Try "Never" if the default "Only with High Contrast themes" isn't working.