Actually,.. not so much the quality as defined by silkie breeder, enthusiasts, or APA/ABA standards. I have butchered many a silkie (cockerels mostly) and find that skin color is NOT always a good indicator of flesh/bone pigment. I have four wishbones from four silkie cockerels (two blacks, two whites, blacks had some color leakage in the hackle and whites were just not typey enough) dyring in the kitchen and only two of the four are black. All four had black skin, dark combs.
The meat ranges in depth of color.
Just my personal experience. I've probably butchered (all the way,.. not just cull,.. I mean clean and cook and eat) around 50 silkies,.. so not a huge sample size but not someone who has butchered a couple birds. None were hatchery stock, some were culls from quite nice birds I've won with.