As a preliminary comment, if you use a "High Contrast" dark theme on Windows, you can instruct Firefox to ignore that. See: Disable high contrast mode in Firefox.

Firefox 95+ is taking more and more cues from your toolbar area theme for how to style other aspects of the browser. There is a setting for some of these, but not all of them.

(A) Right-click context menus, toolbar drop-down panels

Starting in Firefox 89, these would flip to a dark background if the text on the inactive/background tabs was white or light. Firefox 96 has extended this adaptation to more parts of the browser. As far as I know, the only built-in way to avoid this is to change your toolbar theme to one with dark text on the inactive/background tabs. (The other way is the not-officially-supported userChrome.css file route.)

(B) Built-in pages, and websites that have light/dark responsive themes

Starting in Firefox 95, Firefox would inform pages that you preferred a light/dark theme based on your Firefox toolbar theme instead of your system theme. There is a way to decouple your page (content) theme preference from your toolbar theme. At this point, it's only available through the back door...

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste layout.css.prefers-color-scheme.content-override and pause while the list is filtered

(3) Double-click the preference to display an editing field, and change the value to whatever you prefer from the list below, then press Enter or click the blue check mark button to save the change.

• 0 => Force a Dark background
• 1 => Force a Light background
• 2 => Follow the System theme (default in Firefox 94)
• 3 => Follow the Browser toolbar theme (default in Firefox 95+)

The about:config page should immediately reflect your saved change.

I have attached a composite screenshot of what Firefox 96 considers a "Dark" theme (light text) and a "Light" theme for reference. It's difficult to say exactly where that line is....

I should have been more specific in describing the change that has been made by what I assume to be an "update". The background color change is on the Firefox home page. Yesterday, up until around noon, Eastern time, the background was white. Now it's dark gray and I'd like to revert to the previous background color. I've included a screenshot to help clear up any more confusion from my end. Thanks for your time.

Hi, that is covered by "(B)" in the earlier reply. It's a change in Firefox 96 that harmonizes the color scheme of built-in pages with your toolbar theme.

Thank you jscher2000! That worked! You made my day, hope you have a great one too!

Maybe that kind of change should be left up to us users, not sprung on us without a simple way to change it back. I see the reason, but still, users should have that control, not Mozilla nerds. This is the first change that totally annoys me. Way to screw it up.