Since yellow is the result of non-red genes, you cannot have red and yellow on the same fish. The fry would most likely have a varying amount of red and black. If you crossed the female to a yellow male you would get a varying degree of yellow and black with maybe some random ones thrown in.
You can't apply the simple mendelian genetics to betta color since many of the genes responsible for color are on the same chromosome and are inherited together even if they don't show in the fish. That's why you always get a few surprises in each batch :)
I personally love the red male too, but I'm out of room for new fishes D:
Last edited by DarkMoon17; 05-05-2011 at 07:28 PM.