Well, Gabriel doesn't, but Xavier and Dominic have both expressed the desire to be "brown". Each of my children has their own story about "brown" people and I'll tell you each of them.
When Gabriel was 5, we went to the library. In the elevator, there was a little Somalian girl who kept rubbing Xavier's head. I'm guessing she, being a recent immigrant, hadn't been that close to a white baby before. Anyway, Gabriel yelled at her, "Don't touch my baby, you'll turn him brown!" Of course, Gabriel wasn't aware of the concept of genetics, yet...
Xavier really wishes Gabriel hadn't stopped that little girl from turning him brown. In preschool, he desperately wished he had been born into a brown family, a dark brown family. His beloved teacher was dark brown and he wanted to be just like her. He still complains that his family is peach.
Dominic also wishes he were born to a different family. However, he is doing something about it. He is slowly attempting to color his skin brown.
Unfortunately for my children, there is no such thing as reverse vitiligo. Perhaps a full body tattoo might work?