Not surprising, since I believe Firefox gave everyone the Colorways screen when that feature showed up, but nothing equivalent happened whenever it went away.

My current desktop has been Fedora since Fedora 16, and I just upgraded from one release to the next continuously. So yes, whatever choice I made back in 2013 is just going to stick around on my current machine unless it goes away entirely or I manually change it. Colors are just not that important, if I like it well enough, it's going to stick around forever.

The only one that caused intense feelings in me was the "Dreamer – Bold" theme that caused a fair amount of confusion about why the heck couldn't I tell which tab was active, and what could be possibly broken. Because it never occurred to me that the theme could be designed that way intentionally.