If it's a sort of pinkish, greyish bluey colour then as diamondlil said she could be getting ready to shed. If she is, you may find that she will hide more and become a bit more skittish over the next few days to a week or so, until she has completed her shed. This is because their eyesight is impaired during this time and they feel more vulnerable, but it's absolutely normal.
Hope that helps some, best wishes,