I just switched to Mac OS Catalina. Of course, there's always some kinks along the way. This time, all of a sudden, Firefox is highlighting selected text in blue. This ONLY happens on Firefox. The default system text highlight is YELLOW. In all other apps, selected text is highlighted in yellow. I have played w/ the Colors setting on Preferences, setting it to use system colors as default. No difference. Interestingly, ON THE PREFERENCES PAGE, text highlights in yellow. However, on any other website, it highlights in blue. Obviously this is very, very small. But it's driving me crazy.