were they the factory finish? If so, they are painted, not powdercoated. Regardless, 90% of my pc business is brake calipers, and I do on average 5-6 sets per week. I never recommend powdercoating for cars that see track usage, although my own experience with several track outings is that I haven't had problems. I think I am just easier on the brakes than most however, as my gold 350z brembos never turned dark after several events when most people who track theirs turned dark brown.
Another side note, the darker that factory paint gets, the harder it is to strip off! unfortunately.