I remember as a teen noticing how our chickens would naturally segregate into different groups according to feather color. It is very common to see it yet today in pens with mixed varieties having their own little cliques, with the buffs all roosting together and other varieties off to themselves.
What I've found interesting lately is that a neighbor, about a half mile away, has chickens, ducks and turkeys free ranging and the white ones of all three species flock together...as the saying goes. The two ducks and two turkeys are white, along with one chicken. The other chickens are of mixed colors and even though close by the white birds they are generally several feet away.