These are from Ideal so I doubt mixes. They aren't Sebrights because they have single combs and feathered legs--I did see some I was sure were Sebrights in the bin, though; those have rose combs and clean legs.
Ideal also sells Brown Red D'Uccles, but I thought they were almost solid black as babies, so I'm just not sure. If you look on Feathersite, there are some really dark ones there that are labeled MFD's, but since shades can vary slightly in the same color family, I just may have to wait a bit. You know how much we all love waiting...um, no.