if these are true sex links, they are auto sexing. the roosters should be yellow, the pullets should be a sort of amber color, as day old chicks. the yellow (males) should grow to have some white feathers. the colored (pullets) should grow to be solid color that is if they are true sex links. looks like you were given mostly males. bet you didn't hatch these yourself. it happens often with all sex linked birds. they let the tiny roos go, and keep the pullets, simply because one can tell from day old chickens. the pullets are nearly always preferred. that being said. most, but not all true sex links are F1 hybrids and won't reproduce truly. mostly the only way to get the sex link phenomenon is to cross birds like the parents. although some breeds like the cream leg bar are auto sexing and are a true, or (pure) breed. their are others too. poulterers use sex linked birds to select very early the pullets. they don't spend money feeding birds that won't lay eggs. most sellers won't let you pick the birds, if so, you could also pick pullets with this type of chick.