interior dye
FWIW, the door panels, visors and dash in my 68 Barracuda were dyed with SEM from Blue to Black over 4 years ago and they still look great. Both the front and back seats were also dyed at that time but the back seat upholstery was changed last spring to new black but the dyed had stood up fine.
Two years ago I also picked up a seat that had perfect upholstery in white and dyed it black and it still looks great but needs to be touched up from time to time if I scratch it.