This may be a dumb question but here goes: I have a new Lazer 23 Kohler, 52" Hp. Whenever I go up too close to a concrete surface and go up on the concrete a little the anti-scalp wheels leave a dark black skidmark on the concrete surface. To me this looks bad. I try to be careful but sometimes I can't help it. My question is: Why are these wheels black? Couldn't they be made a clear color so they wouldn't leave these black marks. Sorry if this is a dumb question. Thanks for any help.