I actually just had an experience with this last week. I was in a dream and got off my bed. There was a full body mirror next to me and I looked into it. I had blue eyes(I have brown in RL), lighter hair, and thinner eyebrows. It was so creepy. I also saw my hands and they looked REALLY weird (Like I figured they would)....all of this in a normal dream haha.

Very creepy experience I must say