MacNN reports that Apple actually is fixing the rampant discoloration issues present on white MacBook laptops. My laptop suffers from this issue, even after I had put an invisible shield on the palm rest. The discoloring stems from a manufacturing defect in the plastic. Apple will replace the top case, presumably free of charge. Hopefully, I will just be able to take it into an Apple store and have the plastic replaced while I wait. Derek has created a nice timeline of his troubling MacBook issues.