don't know if BBS is any different than blue, but after googling, they look blue to me... LOL...
in that case, you will only need some blue or even splash hens...
breeding blues is simple...
splash x splash = 100% splash
splash x blue = 50% splash 50% blue
splash x black = 100% blue
blue x blue = 50% blue 25% black 25% splash
blue x black = 50% blue 50% black
black x black = 100% black
you can get a nice splash hen, and make 100% blues very easily... we have blues... i'm waiting for a nice splash hen to pair up to my khaki roo to make platinums or whatever... LOL...
i also have blue giant cochins... but don't have pics of them...
HTH...