The ‘opacity’ slider (when selecting the colour) can be changed to make it less in-your-face, but it is not “sticky” (a bug - I’m on ubuntu 20, kicad v7.0). Haven’t bothered to find out exactly when it reverts back to full strength (too many other things to do), but no doubt someone will get around to fixing it at some stage, and it really is just an annoyance, not a show-stopper.