When they are a week or so old you will only be able to see one row on the hens. As they age their comb developes and you can see the 3 rows clearly. I think at that age if it was a he it would be fairly reddened but it is so hard to tell when you don't have a roo & pullet together for comparison.
If its not raining after work tomorrow I'll try to get a picture of both Rosemary's head and the heads of the two Dark Brahmas.
The dark girls' combs are much smaller, but they are also much smaller and their feathering seems to be less well developed. Rosemary didn't read any of the information about Brahmas being slow to mature.