if i rememeber correctly its the silver gene used to make red sex links. not necessarily white. also, there are two different kind of white dominant and recessive. sounds like the leghorn uses a dominant white gene because all of the babies came out white. if it had been recessive white the babies should have came out red(ish) but would have been split to white. most breeds people use to make the red stars are a RIR roo and either SLW, delaware, or white rock hens. black stars are usually made with RIR roos and barred rock hens whereas the male chicks will be black with a white spot on the head and the female chicks will be all black. please note this is to the best of my knowledge. anyone else feel free to chime in.