We get ours...from a local chicken "farmer" who has broiler houses. He raises chickens commercially, and the food markets only accept white chickens - darker birds' feathers make the meat look a little darker. Anyway, all of the darker day-old chicks that are delivered to the broiler farms are culled - aka KILLED because they can't use them. IMO, getting these chicks is a good way to save some them from a horrible life of confinement, overfeeding, crowding, and only about a six week life-span. And they're free for us.
Before thois was an option for us, though, we bought our chicks from "Ideal Poultry" and had great results. We ordered Rhode Island Reds, Golden Sex-Links, and Barred Rocks. All of the chicks arrived in great condition and healthy, and they even included a few extras at no cost.