The cockerels coloring looks fine, other than the fact that he has no white (he should get some soon). The pullet however, she's different. Not sure what to call it.
Booted bantams (sablepoots) are basically a d'Uccle without a beard. They have a few color differences, but I believe their recognized show varieties are the same.
Try baiting the nest. Put eggs, or golf balls into the nest and make a large clutch. Probably around 5 eggs. Then keep her in the coop so she can see it. Hopefully she'll set.
It's hard to tell with cockerels, especially d'Uccles. I would keep him until he's around 6 months (if you can), then make the decision based on what he looks like then.