"Sex Link" is not a breed, but more along the lines of a breeding method.
any time a Red rooster is bred to a Silver hen, the female offspring will be pure red. and the roosters will be red/silver split.
This is because hens only carry one gene for the Red/Silver locus. They inherit this one gene from their dad every time. Roosters carry two, they inherit one from mom and one from dad. So a Red rooster over a Silver hen will always produce red hens. Any other color is due to other genes present in the parent breeds (or varieties or what have you.)
Thus any Red rooster bred to any silver hens will produce pure red hens, which are easy to identify when compared to gold (red/silver split) which will all be roosters.
on to another subject.
The layers I had which were Buff Rock X Red Sex Link did vary some in color, from nearly pure white to dark red. But their laying didn't vary hardly any at all. The Buff Rocks were a very good laying strain. Obviously the RSLinks were too.
One day I want to breed birds like that again. Right now I have too much going on with the longcrowers and longtails.
The Longcrowers are really good layers by the way. I would love to see someone breed one of these boys to some big laying type hens to work with a few fun genes. If anyone here is interested let me know.
All chickens are hearty eaters, right? WHat kind of other animals do you have? If you have goats, horses, or rabbits, you can turn their manure into compost and use the chickens to turn the mulch. It is actually good for them once it has gone through a heat and decomposed a bit. It has lots of bugs and worms and mushrooms after it is finished, and makes the chickens really shine when they have access to it.
A big compost pile can actually provide enough food for several chickens, in combination with a little yard space (aka pasture)