Maybe a silver Deathlayer rooster. I guess he could be Campine x white Yokohama. A good shot of his comb would help determining what type it is, and that should give the answer. Or at least help.
But as far as titles go for color varieties, birchen is silver based and brown red or copper is gold based. Birchen is used as an umbrella term in genetics. That's how I learned it, anyway.
She's not blue copper because there is no copper in her plumage. But she could be blue birchen, a similar pattern where the copper is replaced with silvery white. Or she could just be a barnyard mix. I would judge by egg color once she starts laying.
He is a blue wheaten Ameraucana cockerel. As far as niceness goes, individual personality is more important than breed in determining behavior. That said, I have not heard of any aggressive Ameraucana roosters. If he's well behaved now chances are he will remain that way, but really it is a wait...
Pearl Onyx are Mystic Onyx, which are a mix with Silkie involved, crossed with white Leghorn. I saw nothing saying they could be sexed using skin color. There are now several of similar hybrids sold under various brand names by the different hatcheries.
It's one of many autosexing breeds. I think these are Rhodebar male over New Hampshire female. I'm betting since these seem new that the autosexing traits are not strongly defined.
Wheaten can be variable. Some darker, some lighter. I think you just have some darker genes with these, probably from the father.
The birds in the last three pictures, if they are the parents, are definitely right for wheaten Marans.
Those two do look to be cockerels at this stage, but the breeder is probably gonna want them to look more definitely male before exchanging. Maybe not. I'd ask.
The brown chick looks like either a light crossed with partridge or a buff crossed with dark or partridge.
It's just such a rare breed that there isn't much to go on. I hope you get a female, but unless someone more familiar with the breed comes along, I think it is a waiting game.
From what I read, males won't have any black spotting on the down feathers when they are chicks and females should. So that may be one way to tell, if you can remember to how it looked when younger.
Conversely, feathered out males seem to have black tails and wing feathers, with barring. This...
The white one has a pea comb, so probably some type of Easter egger.
I'm guessing Australorp for the black one.
The last one is some kind of red sex-link, or maybe a Starlight Greeb egger.