Many hatchery pullets are on the darker side. At 13 weeks old any boys should be obvious with a redder comb, light hackle feathers, black body with light brown to reddish brown back.I have 6 salmon Favs from Meyer Hatchery. I have 2 obvious females in the layer coop now, but now worried I have 4 other girls but are darker colored..... They are 13 weeks old, boys might not have a comb yet right?