No such thing as Americana. There are Ameraucana, Araucana, and misrepresented Easter Eggers. Three different things. Easter Eggers aren't really mixed breeds at all. They just haven't been bred to meet a specific standard. But no, I don't think any of them are Easter Eggers either. They are...
All Orpingtons, regardless of plumage coloring, should have white legs/skin. Yellow skin is a major disqualification, meaning that a bird with yellow skin would not be considered an Orpington at all.
The picture posted shows a Blue Partridge Orpington and a Silver Penciled Orpington. Neither are...