It comes off in the wash
My Yokos get ugly brown patchy areas after using tire shine then not washing it for a while. Prior to using the tire shine the first time they were black. The brown does wash off though, also the side of the car that gets the most sun in my parking space gets browner. Not to be idiotic but I think the tire shine breaks down in the sun, yellows or tans if you will, leaves brown residue. I don't use wheel cleaner. I'm planning to change the brand of tire dressing to a less shiny one anyway, so we'll see. Best other guess is that it's some chemistry issue w/ the Yoko rubber formula reacting w/ various substances, sun, heat, dirt, cleaners, dressing, whatever, that's probably beyond us unless you want to have it laboratory tested.