Combs do not appear as simple as some of the gene sets.
From what I've understand from several sources:
Rrpp, RR,pp provide rose combs
rrPP, rrpP show as pea combs
rrpp provides single combs
RrPp, RRPP provide cushion combs
But the other aspect of the cross besides leg color in my mind is really egg color. If you cross into a strain with dark brown egg color, it will probably take a long time to get back to blue egg color. Buff egg color is still suffering from the buff orp crosses way back. I seems that the brown egg color is much darker in the red colors most of the time. Silver genes in AMs usually have better blue color. Its too bad that there is not a red bird with slate legs and at least white egg color. Most of the time you would at least have to breed out white ear lobs too.
Gordon, it would be great if we had a counterpart in the bantam version to go along with any project in LF or vice versa. But we've had folks start a color in one or the other before and later someone will take on the project of translating into the other size. I know that we've had folks working on several colors over the past number of years. Most often I think in the past they started with bantam and then breed up in size.
Birchen, Columbian, Buff Columbian, Mottled, Cuckoo Lav, Partridge, and Chocolate have all been started at some point in one or the other. I don't know if there are LF projects with Chocolate out there to go with bantams starting now? But then you have the natural offshoots of some other colors like Splash and Splash Wheaten because folks are breeding the Blues and Blue Wheatens. These are easier because you already have the parent colors progressed in traits of the Breed. So there are lots of projects for people to work on, and then there are the 8 accepted colors that still need progression too. Plenty to interest anyone who wants to take on an accepted color or project color.