Given the condition of the animal, I think it's very likely that she's undergone a stress- or hormone-related color change. It's not all that common, but is not unheard of. Give her a few months and a few sheds with regular meals and solid husbandry, and she may revert back to her original coloration. Now, whether that original coloration is what we consider "normal" who can say?

In the end, I think she'd need to be proven out through breeding to find out if anything really genetic is going on. Regardless though, she's beautiful, and I'm thrilled that she's finally found herself in a good home!