I really dont know much about chicken genetics....
...but one of ours hatched with yellow feathers (Like the light sussex) the marans looked like tiny penguins - with black jackets on. As he grew, he got a gingery back, then black feathers, and now seems to be a black copper maran cockeral, with the other three as hens.

he's known as "Oddbod"
my o/h still insists he came out of a white egg!