But once you did hit that 8 dominant/co dominant gene combo (probably with the help of some homozygous parents, like a super pastel +3 on one side and ivory +3 on the other side for only a 1 in 64 chance of the 6 genes not guaranteed like pastel and yb) when you breed it to normals the eggs would only have a 1 in 256 chance of hatching a normal. You might breed a 8 gene combo its entire life and never hatch a normal regardless of what you bred it to.