They look to be silver appleyards but they could also be welsh harlequils. If you could post a side picture of one of them that would help greatly. The white one is a pekin.
The only way to tell is if it lays an egg, has a penis, or has male curly tail feather. Here is a pic of a male pekin he has the little curled feather at the top of the tail.
Also, looking closer, I believe you have 1 welsh Harlequin as well. The dark billed, multi-colored one. If the Pekin quacks it would be a girl. A rasp, would indicate a Drake.