The chicks down will be replaced with their feathers and they may change color when the feathers start coming in. If you bought your chicks from a feed store they could have mixed the chicks up. I usually hatch out my own chicks but a few years ago I bought some chicks from a feed store because the sign on the tank for breed I was looking for said Brown Leghorns. As chicks there are many breeds that look very similar, I ended up with Partridge Rocks. I did eventually find a breeder with nice Brown Leghorns. Good luck and have fun...