I'm not that fussy over having correct genetics, but don't give your cat red eyes or purple fur. Examples of bad designs:

Black cat with white stripes
Black or brown with golden spots
Every colour combined in a crazy tortie
Bright blue. Just blue
Bright yellow. Just yellow

I have a few questions. How does Graystripe and Millie make Blossomfall? And what colour is dark ginger?

* Who cares, have fun with your designs. It's better than having 7 cats just labeled as "brown tabby." Some designs push it more than others, but at least it's not boring.