It depends on what breeds you're working with, I suspect. If you are making black sex-links (RIR C x BR H) the barred male offspring would have a white dot on the top of the head while the black female chicks were solid black. If you're talking about general down color differences between a black feathered bird (Australorp) and a barred bird (Barred rock), the true black bird would have black down with a white belly whereas the barred rock chicks would me mostly black with yellowy/white dots on their heads and wings. I think barred rock male chicks look more patchy than barred rock female chicks, almost a grey/white mixture. That is what I have seen in the chicks I've hatched.