That is correct, you can’t have homozygous Sharp that has BWC or prodigy genetics. The allele that makes a genetic mutation is 2 parts. 1 from the father. 1 from the mother. An animal carrying 1 allele copy is heterozygous carrying 2 is homozygous. Carrying 0 is normal.
Hypo and Motley are 2 different mutations that are on the same allele also. If you breed Hypo to Motley you get hypos, Motleys normals and hypo Motley. If you then breed one of the hypo motleys to a normal, half of the animals will be hypo and half will be Motley.
I’m in my phone so difficult to explain fully. I’ll get on my computer later and check in.