Hi phonyaddress, Firefox 73 introduced the idea of a "backplate" for certain elements to make pages appear closer to their authors' design when Firefox applies a high contrast system theme.

Did you change the backplate setting already --

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

(2) In the search box above the list, type or paste backp and pause while the list is filtered

(3) To revert to the behavior in Firefox 72 and earlier, double-click the browser.display.permit_backplate preference to switch the value from true to false

Or is that working differently now?

jscher, I applied that fix to the previous update to remove the black bars in High Contrast Mode. After this week's update, there is this new issue where the tab background is opaque against the web page.

For example, I tried to transfer funds in my Fidelity account, but when I clicked the Transfer tab it appeared with an opaque background which made all of the prompts invisible against the main page.

The updates are wreaking havoc for those of us with low vision who depend on High Contrast in order to see.

If you revert the setting change and turn backplate back on, has it improved from the way it worked in Firefox 73?

I don't think I know what the Fidelity website looks like, so I can't predict which way will work better.

I switched back to "True" from "False", and the black bars returned. With regards to the opaque tab, the prompts are displayed against a white bar, however, the background is still opaque. It's rather blinding.