Are Barnevelders not good layers? Instead of creating a cross why don't you breed true Barnevelders and breed for both type and egg color, they sure could use some attention. If you cross 2 birds each parent is going to contribute to the chicks but it depends on what is dominate and what is recessive in each parent and what they will mean to the offspring.
Edited to Add:
I would get the BEST Barnevelders I could get my hands on and begin there. I am not sure if they are an APA accepted breed but there are breeders out there can can give you that information. So choose the best Males for type and they best females for type AND egg color and breed them together and continue from there until you are getting good hatch rates with birds meeting you criteria.
Good Luck, it is a lot of fun