Yes, he could be pure, but he may also be a poor Birchen Marans - size and body type point more toward that. You can't know for sure without a lot of test breeding to see what color egg genes he carries. If you use him in an Isbar breeding program and he doesn't carry the blue egg gene, you could put a lot of effort in for nothing. At least with a pullet you can make an educated guess on breed by seeing what color egg she lays. If you are serious about wanting to start an Isbar breeding program, I would get eggs/chicks from a source you can trust that they are what they say they are. Since it sounds like you didn't order Isbars, but ended up with these, you really can't be sure what they are. In my book, it is not worth the trouble. I have a few of those myselfThanks! It's good to know that there is still a chance he's pure. He is pretty big and I'm assuming he's from the new line of isbars. Since this could be an over pigmentation problem, should I cull him? I have another one like him from another order of bresse but I'm pretty sure that one is a cull as his comb is starting to flop. I have another "bresse" that has some gold on the wings. He's a blue bresse and I have seen a picture of them having a few gold feathers here and there, but this one looks again like an Isbars wing. I'll try to post a pic later today to see what you all think, but he doesn't have any color in his hackle that looks isbar. I am going to be taking some pics to send to the breeder to see what they say. At this rate ime not sure any of my bresse are bresse. I was planing on getting some Isbars this spring from a different breeder and thought it would be nice to have this boy to add to the gene pool. I guess I have a "legitimate" problem here and will be talking to the breeder yet again.

My new line juveniles are still too young to evaluate size, plumage color or egg color. So far, they don't appear to be too different from the original line juvies growing up with them.
I do know that I like the small size and low feed requirements of the original line and plan to keep at least one breeding pen of pure original line. If the new line ends up being too big and bulky, I am not sure I will continue with them. But that is my preference. Others may like a bulkier Isbar and it may have its own attributes that make it worthwhile. But the characteristics of the original line deserve to be preserved, and as much as I want to add diversity to my flock, it is not worth abandoning some of the best attributes of the Isbar. If I don't like the new line, I will sell them off and keep 2 or 3 pens of the original, adding diversity by obtaining eggs/chicks from others who have the original line (which I plan to do either way).