http://welbars.com/index.php/welbars/isabel-welbar/
These are the F5 birds on that page. I am now raising up the F6 generation. They hatched from eggs that were dark green, but the blue egg gene is not homozygous in every bird.
Once they start laying, I intend to send blood samples for genetic testing and hope to get a pen of pure Isabel Welbars (no blue egg genes, lay dark egg like the Welbars they came from) and a pen that looks the same, but lay dark green eggs and are homozygous for the blue egg gene. I need a way to differentiate them from the other lines, so I decided to call them "Jade Welbars" to indicate the egg color. I also have a few birds that are gold like a normal Welbar, but are siblings of the Isabels. If any of them test homozygous for the blue egg gene, they can go into the same pen and any gold (non-isabel) chicks will also be Jades, and so I can keep both colors in a single pen.