I don't know about the feather color but I can tell you that the recommended male to female split for ducks is 1 male to every 4-5 females. I know some that have a one to one ratio with no problem but you are really risking over breeding and/or injury to your females.I have 6 sweedish ducks and I'm not sure how many males and females they are 6 weeks old and some are quacking so i should know soon. My question is 3 of them are larger so I have a feeling I might end up with more then one male if this happens will I need to get more females. There new feathers are a green tint is that an indication of a male or is that something all sweedish ducks have.