Not really. I am in my 50s and have seen, white, black and Asian Dommes. Go to any site for a major city and you have your pick. Most of what I have seen I consider pretty attractive.
Last session I had was in Phoenix. Assuming interests are comparable and I am in Phoenix again If I ran across someone who was 4’6” then I am lining up to serve.
But that’s just me.
This coming from someone who can say one of my favorite all time Dommes was 6’ tall.