Not sure about anyone else but Magnus still seems to change colors. His back was black but saw a little brown coming out and now it's more visible.
Have you tried Madan pin brush? Both Magnus/Zoey STILL doesn't like getting groomed in general but they seem to enjoy it when I use the Madan brush. I have one for myself. It really feels good. LOL
You can get them at
toplinepet.com the owner is a member here (Mimimomo) and I think she offers discount for YT members.