Hi Firefox now harmonises more elements with your toolbar theme. When the text color on your background tabs is light/white, it triggers Firefox to use a dark background on menus, the sidebar, the Library window, and various built-in pages. Firefox also signals sites that you have a dark theme preference. You can download a different theme from https://addons.mozilla.org. I hope that this helps.

A helpful comment on how to deal with the issue: https://support.mozilla.org/en-US/questions/1364418#answer-1474290

Bill, did you read the replies to your thread from a week ago? Nothing has changed in the past week. [https://support.mozilla.org/questions/1363913 RECENT RELEASE FORCED WHITE-ON-BLACK - DESTROYING PRODUCTIVITY.] Maybe some examples of themes that trigger a light color scheme will cheer you up: * Firefox Logo: https://addons.mozilla.org/firefox/addon/firefox-b/<br><img src="https://addons.mozilla.org/user-media/version-previews/full/2927/2927697.svg?modified=1622822844"> * Winter snow: https://addons.mozilla.org/firefox/addon/blue-winter-snow/<br><img src="https://addons.mozilla.org/user-media/version-previews/full/3694/3694543.svg?modified=1622998589"> * Green shoots: https://addons.mozilla.org/firefox/addon/printania/<br><img src="https://addons.mozilla.org/user-media/version-previews/full/3610/3610384.svg?modified=1622979415"> * Great wave: https://addons.mozilla.org/firefox/addon/japan-style-kanagawa-gr-232767/<br><img src="https://addons.mozilla.org/user-media/version-previews/full/3297/3297875.svg?modified=1622907325"> * Kitten: https://addons.mozilla.org/firefox/addon/savage-black-kitten/<br><img src="https://addons.mozilla.org/user-media/version-previews/full/3855/3855669.svg?modified=1626077722"> And there are thousands more...