We bought ISA Brown pullets from Tractor supply about six weeks ago. One of the chicks was much lighter than the others, but the employee there assured us she was a female ISA Brown because she wasn't white (more like light yellow/gold) and she had the darker marks on her back like the other ISAs. (Two containers full of ISA Browns and one lonely Leghorn were the only breeds they had that day.) Well. Now her sisters are mostly brown and she has no brown and is closer to white than yellow or gold (and definitely not brown). Is it likely that she is actually a he? Or another breed all together? Here is Funnel, the chick in question: This is what all of the others look like: Here they are at about a week old. One very light Leghorn (who died at about 2 weeks old), one dark ISA Brown, and our mystery chick.