The coloring is female, but that only is a good clue if they are pure BRs, not a cross. I had some Silver Phoenix x BR chicks and the males were dark like that because they only got one barring gene from the mother. That said, pullets can have different sized combs. My exhibition quality group turns 9 weeks old tomorrow and the pullets have almost no comb, but that said, hatchery pullets generally grow larger combs earlier than the breeder quality ones in my experience. If those are both verified as having both parents BRs and not a mix, they can still both be pullets from the dark coloring. They do carry only one barring gene, it appears, which means female in BRs.
That's all I have for you! At this point, I'd say even the one with the larger comb is female. In a week or two, check the upper back between the wings to see if on the large combed one, a group of skinny, pointy feathers are coming in which would be male saddle feathers. Hope this helps! Let us know.
