Hello everyone...are there any breeds that can be sexed by their down color or bill color etc? Also, I think I may have Swedish Blues...but I'm not even sure of that, they are grayish on back and head with yellow belly and some have black markings on feet and bills. Is there a color difference between Swedish blue and Swedish Black & White as ducklings? Or does it not become obvious until they get feathers? P.S. If they aren't SB...then what else could they be being gray and yellow? Thanks for reading!