I have a California white hen and an RIR rooster. I had originally put 3 eggs in the incubator, there was one blond one that pipped but did not hatch. I just thought it was from the previous owner's rooster.
Are these black sex links? I hatched these out about two months ago, but I don't know what they are. Their parents are an RIR rooster and a California White hen.
Photo from Google: This is what they looked like as chicks.