Wow! Pretty girl. Looks like a blue fawn in coloration, and based on size, I'd go with mallard. I don't really understand duck color genetics, but the color seems unusual for a mallard. @Pyxis, care to weigh in?
She sure does look blue fawn, which makes it even more interesting since she's a hatchery duck. She looks too small to be a rouen, so mallard or mallard mix would have to be my guess. Hatchery must have been doing some breeding experiments, haha.