white black spots

Hi so I got my ducks out of an assorted bin at tractor supply and the employee who helped us said they were white ducks, now that they are older I wanted to confirm (or not) their breed!

Last March, TSC got a bunch of new chicks. In one bin they had Black Stars and Isa Browns. I got both of those kinds, but then they had tons of white chicks with purple skin and black spots. I asked their breed and TSC was clueless, they didn't even know what Black Stars were. They called them...