Do they have yellow feet? In the first pic, the male looks to have yellow feet. Either way, I'd say they are probably poorly bred "Marans" rather than something else entirely. Orps, for example, have clean legs. Did the breeder show you what the eggs look like from his breeding stock? BTW, I have an over-melanized BCM hen that hasn't a hint of the copper showing so I'll also attest that it happens. But, she lays huge, dark eggs.