Quick tire question. I have a brand new set of 208GP's (last years cheap compound...lol) that I bought at Jennings hanging in the garage. I just noticed that the front tire has a rainbow effect of colors to it, almost like water with oil or gas on the surface looks. It is pretty bright. Is this normal or bad? Does it have something to do with being outside...gets the sun during the late afternoon if the garage door is open (not very often), and I guess the garage probably doesn't usually get over 90-95 degrees ever. Help...TIA.