If the lower left chick is the one you are speaking of, I think there is too much grey compared to the chick from MyPetChickens - but then there could be variation - otherwise, seems a possibility. Also,
IF it is a porcelain D'Uccle - very thick/raised comb spot for a girl if it is just 2 weeks - but would say need another 2 weeks or so to be sure on the sex..
The one on the right appears to be yellow based from what I can see (speaking of beak, legs. ) Should be white with grey over legs like one on left and above - and have white beak, possibly with darker spots, not.a full yellow beak. That said, there are other colors of D'Uccles - not just the Porcelain (Milli-fleur D'uccle, etc.) Again, this is just going on picture you posted from My Pet Chicken and a quick search online, I personally know nothing on the breed.
Images of color varieties of D'Uccles
If your TSC gets their chicks from Hoover, Hoover has bantam Buff Cochins (chick on right?)- not sure what else it might be that they have. Might they (TSC) get their chicks from somewhere else, too??

Sorry, that is all I got for you.

. ?Maybe RM will have more thoughts - she has a good eye when looking at pics of chicks/chickens, and quite the reservoir of knowledge on feathering/colouring, so. might have more suggestions.