Hey Cider and Simon... I already read about the blue cornsnake heres the site...
http://www.cornsnakemorphs.com/projects.html
They are still in the beggining phases... but I really dont know what to think of it... I think it would def be cool to have blue corns... but their you go these projects are from "Exotic by Nature" so they have to be somewhat correct in their breeding styles...
Im not sure about the Rainbow Corn... sounds almost like a Hybrid to be... but who knows colors are coming out of the woodworks everyday now! I really dont know what to expect anymore!