The two brown ones are the same breed but look different is one of them a rooster?
>>2086380
The two partridge-colored ones look like Easter Eggers (also sometimes called Ameraucanas). If that's what they are, there's quite a variety among that "breed" of chicken. At this age, I can't tell the males apart unless I watch them interact with each other. The males will be confrontational little assholes, pecking at the other chicks.