Are you certain that it is "white" versus light grey? I just re-read you said cream colored on the chest. This puzzles me. If it is truly white, then I would say they are cockerels. If there's a chance that it is light grey, then I would say they are pullets with cream or rust color chests. There's plenty of experts on here that may have a better answer for you. I raise colored dorkings and have some pretty weird colors grow in. The white on the cockerels definitely presents itself first. I'm interested to hear others opinions on your birds.