Most Columbian are eb based silver and columbian.I know it's a very old post, but I'd love to know how this is achieved.
Light sussex are wheaten with silver and columbian.
Either base can be used but when you use wheaten you don't get the black stripping in the saddle feathers. See pics below.
Since she's a huge light sussex fan and the light sussex are known to have a "cleaner" Columbian pattern I'm sure she was interested if anyone was working that look into other breeds.
Wyandotte
Sussex