[Ishu]

You get 2 chocobos of a certain quality, opposite genders. Race them to A or S class and breed them. Do the same with the offspring and continue. You need different nuts to get different colors/breeds of chocobos and blahblahblah.

However, if you are trying to increase their birth stats, color still has NOTHING to do with the outcome. You have to average the end stats of the chocobos you are breeding and that is close to the beginning stats of the baby chocobos. You can't just breed the same two chocobos and get higher stats, you have to breed their babies, and their babies, and their babies and so on just to get a 10 point increase at birth.