On the first one looks like its feet are too yellow to be a buff orp... The barred one looks rooish... The rest, I'm not sure. Sorry, I'm not real good at this
The last pic is hard to tell. Someone said SLW so I posted a pic of my slw roo at a few weeks of age. The other picture is my BO pullet so you could see how white her legs are. Maybe comparing pics will help...
Does the black one have black feet?
Maybe it's a black-sex-link. I have one of those too