Bev Davis was working on hers using the Salmon if I remember correctly. The GCMs I have look like they have wheaten or maybe btb but if it's wheaten the color is very dark on the hens which wouldn't be SOP so I don't really know but I am planning on using either mossy BCM or too dark Wheatens with mine to improve the egg color since I happen to have Wheatens that have very dark eggs and some of the hens I have are too dark for SOP......I'm working with what I have.