I'd agree that they are probably mixed. I too thought the first two chicks resembled Rhode Island Reds, but feathered legs clearly aren't in their breed Standard. The last chick reminds me a bit of a Blue-laced Red Wyandotte that inherited two blue genes and is actually Splash-laced Red. But the color isn't quite right there either. So maybe it is a Silver or Gold-laced Wyandotte mixed with something.