The fact that we're in the PC forum means nothing. People drive the wrong way on the interstate all the time. In other words, people don't pay attention.
The answer to your question as to why your character's skin went from "pale" to "redguard" is not something we can answer. That's one for the devs. My guess, and that's all it can possibly be, is that they decided you can't get "paler" so in order to make a visible change it could only go darker. It'd look pretty silly if you were just a blank white spot with no detail.
If this is the only problem you're having with Skyrim, I'd suggest you just go play the game and enjoy it.
