hightlighted text color is suddently invisible.
Suddenly when I highlight text to copy, the highlighting color is invisible. The text is actually selected because I can copy it. I have been through all of the previous help, System settings:Appearance:Highlight color. I can select the color, etc. quit system settings but still no color on highlighted text. This is the same on the iMac screen and a second monitor. Restarting has not helped. This is an M1 iMac, OS 15.3.2. It was working just fine. I was playing with some of the settings to change contrast and brightness when suddenly I noticed the problem. All of the previous help simply covered how to set the highlight color.
Any ideas?