What are people’s thoughts on RP’ing as species that aren’t technically playable?

I’m not really an RP’er, but I do like making up backstories and stuff for my characters.

How would people react if I made a pink Mirilian and said I was a Zeltron, or something super pale and said I was Umbaran? Would people roll their eyes that I was trying too hard to be special, or would it be fine?