I recently downloaded Firefox and would like to use it as my primary web browser (M1 14" Macbook Pro). But my Google calendar web site is not showing any colors, making it hard to use. On my other browsers (Brave, Safari, Edge) it works fine . See screen shots below from Firefox, Safari, Brave. I have tried re-booting Firefox, the computer, reverting the Firefox theme back to basics etc., and searching on line for a solution, but I can't find anything. So far all other websites are working OK, except for 1 other that has partially the same problem. If it can't be fixed I'll stop using Firefox, which I otherwise like.

Thanks for any help.