In an interview with Ina Fried at AllThingsD, Phil Schiller and Steve Jobs gave a little insight into what made the white iPhone 4 so tough to produce. Actually, it wasn't really the manufacturing itself, but the materials science needed to make sure the white iPhone was in every way as capable and durable as the black-painted iPhone 4.
Schiller told Fried, "There's a lot more that goes into both the material science of it-how it holds up over timebut also in how it all works with the sensors." There's also a reference to how the white iPhone needs more "UV protection" than the black one, which I would guess comes fro
