That's not entireley true. Ugly animals can throw nice looking animals and vice-versa.

I bred a Nice looking Pastel to a high white Spider a couple of years ago and ended up with two high white smoking hot Bee's and two browned out Bee's. I bred one of the browned out Bee's to a Normal and ended up producing 2 nice looking Bee's and one Browned out Bee.

Obviously, you would want to buy the best quality animal you could.