My menu items are now (9/7/2021) White and double-spaced. Why does FireFox change things that don't need changing with no path back. First, they changed menu color to default to another (I think same as Toolbar color) with no recourse. Now the menus are white and double spaced (today! out of the blue sky!!). FireFox, at LEAST make these features configurable. Why do you do this?
Hi r.j.dill, more vertical space was added between menu items starting in Firefox 89 as part of the Proton redesign. There was a temporary preference in Firefox 89-90 to use the old menu style, but that was removed in Firefox 91+. There is work underway to offer compact menu spacing as part of the Compact density setting in Firefox 93, but that's another month away.
For now, there is an unofficial, community-supported workaround, which is to apply your own styling to the menus. This involves setting up a userChrome.css file. If this is your first time, make sure to set aside 10 quiet minutes to work through it.
The full instructions are in the following reply: https://support.mozilla.org/en-US/questions/1346577#answer-1435049
It's also possible to use custom style rules to modify the color scheme, but the details depend on whether you use an add-on theme and what colors you would like.