Black Rings are exactly the same as Cream/Bone. The company that made the originals, Hughes Plastics would add a carbon black tint to the Butyrate when they were molded. Colours varied as the CAB material would be a slightly different shade each batch. You also need to factor in the enviroment in which the guitar was played in. Anyone who was a smoker(and most folks were in the `50's-70's) will have the rings darker as the CAB is porous and smoke/nicotine will be absorbed by the rings just like is is with lacquer. I once had a Strat that was a pale gray colour. After playing it in a club for 5-6 months, 5 night a week back in the early `80's, it turned "baby-shit yellow". I would gather that the rings when new, were pretty stark white/cream vs 56+ years they have on them now..