Well in my experience the roos have more brown on their wings and neck. This becomes readily apparent as their feathers start coming in. However, my birds are from two well-established breeders, so this may hold true only for these specific lines. As we all know, the variation in color corresponds directly with the quality and breeding of the parent stock. I think if you have hatchery stock, you are probably at a disadvantage, as their get shows greater variation in depth/richness of color. There can be outstanding specimens mixed with those more of a "ho-hum" coloration. I am a comb inspector too. I am counting points, so I look at my chicks combs often. I agree that the roos typically have more pronounced combs in size and shape. I notice definite differences around weeks 3 and 4. Hope this helps!