Very pretty chickens. They look very happy.
Chickens make wonderful pets, and I love all of my chickens. They have individual personalities, are intelligent (most of the time
), curious, and full of interesting behaviors.
I am sorry to say, the largest chick, the white one, looks like a Cornish-cross. These are friendly birds, but they unfortunately rarely make it past a year of age due to being bred solely for their meat and not for their health or longevity what so ever.
Make sure to keep his/her growth down by not giving free access to food (have set feeding times) and make sure to be careful of its legs (they are prone to leg problems, over-heating, sores on their chest and heart-attacks). Supply soft bedding so that its chest isn't hurt when it lays down and provide low, flat, soft perches, since they can't get up high.
I could be wrong about its breed, I just thought I would give you a heads-up.
Best of luck with all of them!
By the way, it looks like you may have a Buff Brahma (the brown and orange one. Does it have feathered feet?) and an Easter Egger. I'm not sure about the last one.