Why does it happen? Is it bad? Is it a sign I need to go to a more aggressive tire? I am running sport touring tires at the moment, MEZ4's to be exact. I wanted something with better mileage than the pilot sports that I was running. After my little spill the other day I noticed Blueing near the edges on both the rear and front. I have only heard of race tires doing this and would like some more info.