I didn't do well with my first effort at incubating eggs collected from my hens. I started with seven, and only hatched out three, one of which was so badly deformed (to include eyelessness and heavily leaking bodily fluids) that I had to perform euthanasia. The other two are perfect little chicks (now five days old). My title question is asked because one is solid black (the white wing tips she hatched with are fading away fast) and the other is light golden brown with narrow, black, length-wise, stripes. They are both from a cross between Rhode Island Red hens and an Australorp rooster. Can I assume that their color differences indicate that one is a rooster and the other is a hen, since "sex-linkage" is a characteristic of cross bred chickens? If so, is there a way to tell which color is the rooster and which is the hen? Or is sex-linkage only a characteristic of certain specific crosses? Thanks.