I have almost 3 week old ducks that I got from our feed store in a bin marked assorted ducks. One is all yellow, beak, feet, legs and festhers. The other was smaller and has a marbled color beak, pink feet, black legs and is silver to black in color with a lighter gray below the neck(high chest area). But now that we have had them for almost 3 weeks the silvery one is bigger. Any idea as to what kinds of ducks they are. this site isn't letting me upload pics.