Aye, I was always sad that Wendy un-darkened teir. :( I have a hunch that they thought about his lineage (ie, go-back) and concluded that it wouldn't make sense for him to have skin that dark.
But, poo, I say. He's not a night dweller. If he's out in the sun on the open plains for a very long time, there's every good reason for him to be very dark! Certainly darker than she colored him there, anyways.