hey all, my tele is done up in a 60s blonde poly finish, a little more transparent than the 60s blondes (i guess about the same as the background of tdpri). when i got the guitar, i replaced the pickguard (guessing it was an "aged" or mint one that had further yellowed too much with age) and the stainless bridge to the stamped steel plate. underneath both the pickguard and bridge the guitar has faded to a yellow darker than the rest of finish, instead of the other way around, where the unexposed areas are lighter. any idea what would cause this? just curious.