Hi, is it possible that Firefox thinks you have a "dark" system theme? Here are two way to override Firefox picking up dark theme cues:

(1) For the toolbar area

On the Add-ons page (or in the Customize panel), choose the Light theme. More info: Built-in themes in Firefox - alternative to complete themes.

(2) For built-in pages -- and pages that theme based on your system preference

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

(B) In the search box, type or paste ui.systemUsesDarkTheme

(C) Firefox should display a bar with some radio buttons to choose a new preference type, followed by a + button. Choose Number and click the + button:

(D) Edit the value to either 0 (Light) or 1 (Dark) and then click the blue check mark button or press Enter/Return to save the change.

For reference, this value is used to answer web pages' inquiries about your preferred color scheme. Setting it manually overrides Firefox answering the inquiry based on your system theme.

Success?

Hmm, one other thing. If your system uses a "High Contrast" theme Firefox will try to honor that by simplifying a lot of formatting, and this leads to missing background colors. To override that, go to Options/Preferences --

• Windows: "3-bar" menu button (or Tools menu) > Options
• Mac: "3-bar" menu button (or Firefox menu) > Preferences
• Linux: "3-bar" menu button (or Edit menu) > Preferences
• Any system: type or paste about:preferences into the address bar and press Enter/Return to load it

-- and scan down the page to the second section, "Language and Appearance". Click the Colors button.

Below the label "Override the colors specified by the page with your selections above" change the selector to Never to bypass the High Contrast theme adaptation.

Then click OK to save the change.

Any improvement?