Plymouth Rocks are really great free rangers and come in several colors including barred, blue, black, splash and partridge. Not sure if you wanted something more exotic, but your more exotic breeds usually are not known for their foraging capabilities.
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They'll still be Rocks, just some would be non-traditional colors. Blue/Black/Splash all are meant to be bred together, though. Many breed barred to those as well. If you breed barred rooster to splash hen, the chicks will all be blue barred. Laying ability will be the same. The only color I mentioned that I do not have is the partridge. They also come in white, of course, but I'm not partial to white birds, generally, and many believe that white birds are more easily seen by predators while on range.
Partridge rooster x Barred hen=Black Sexlink
Buff rooster x Barred hen=Black Sexlink
Some White Rocks have the correct color genes to make Red Sexlinks, others don't. Depends on the strain. Only way to find out is to try crossing them and see what you get. But assuming they do have the proper color genes, you can make Red Sexlinks by crossing...
Partridge rooster x White hen=Red Sexlink
Buff rooster x White hen=Red Sexlink