How about only changing the selected text color? I tried making it white, but whenever it becomes unfocused, it turns black.
In this case are we talking about your Summit and Valley themes?
If so then you can fix this by changing the color of Fonts, Colors, & System Metrics > Fonts & System Metrics > BTNTEXT to anything EXCEPT pure black ( even 0,0,1 will do the trick)
Works when testing those themes anyway