I noticed that my idler pulleys are becoming polished(paint coming off) like the sc belt has spun through them without the idlers turning. the belt also looks a little worn on the outside. I don't think the belt is slipping on the sc itself no abnormal wear on the inside just through the idlers. I have a 4# lower. Is this normal wear or what?

 

It's normal for the belts to polish off the paint on both the supercharger and the accessory drive pulleys.