Ihave a project pen working on developing blue mottled bantams. It consisted of two blue roosters. a few black mottles, and a few blue hens. Out of about 60 chicks I got a few blue mottle splits that I'll continue that project with, but I also got some "columbian/birchen" marked males in both a silver based and gold based on both black and on blue body colors. A few have colored feathers on the backs and/or sides. (Its looking like rain but I'll try for photos later). Neither the silver or golds are full like a normal birchen or columbian. Being that they are on dark bodies, I can't tell if its a birchen or a columbian factor. They are a bit attractive especially on the blue body and I might add yet another project pen if I can get a handle on what genes are involved. Interesting none of the hens show any of this coloration so I'm leaning toward a birchen influence. Thoughts?