I don't like the new properties panels icons

I much prefer the way the rhino 5 icons look. Look at these:
rhino 5:

rhino 6: hardly visible icons: (faded and less clean)

especially the current active ones in white are almost invisible

Agreed. I logged RH-49101 about a month ago. We’re pretty sure we know how to fix the fuzzy, but we might need to do some graphical clean up on these as well. I’m glad you spoke up.