My chicks are almost 4 weeks old. Do they keep or lose the feathers that they are growing now? If they do keep these, are these feathers going to be an undercoat that gets covered with new feathers? Do these feather colors change, get more defined? I'm asking mostly because my Delawares are getting a lot of black through their wings and on their upper backs. I was under the impression that they were mostly white with black in the neck and tail. So I've been wondering about feathering out, feather structure and things like do the new feathers bother them, are they stressed when growing new feathers...etc. I've tried googling it and I'm not finding anything.