For the Buff Orpington, I think it is too young to tell yet.
For the one that is gray, black, and white: it might be a Silver Laced Wyandotte or a Silver Laced Sebright, although there are other possibilities as well.
I can't see the comb or the feet, and both of those can give useful clues about what breed the chick is (Wyandotte and Sebright should both have rose combs, Wyandotte would have yellow feet while Sebright feet are a blue/gray color.)
Do you know if the chick is a bantam? Sebrights are bantams, Wyandottes can come in both standard and bantam size, there are some other breeds that come in just one size or the other.