Thanks. I don't know much about colour genetics, she's just never had black chicks before, so I was just guessing. Of the last 20+ chicks she's had, spread over 3 hatches, they all looked exactly like the ones in the picture, and the only roo I kept long enough to tell feathered in like their dad. I can try to get a pic of the other roo if he comes close enough again.
ETA: I was very surprised to see black chicks, it doesn't seem to make much sense. Maybe she roamed further than I thought and was mated by completely different rooster?
Yeah, makes sense.
That's possible. Are there other roosters around? Do any chicks have feathered legs (even just a little), beards/muffs or any other dominant trait that would indicate a different parentage?
Or, could the eggs have come from a different hen?