I crafted up a leather vest and was able to dye it brown using regular ol tree barks. I wanted to check out the black version and collected nails to dye it black but I was unable to do so. I thought perhaps I needed to bleach it first and located some disinfectant spray to do that and could not do that either. I dont know if this is fully implemented yet or if there is something I dont know. Im not sure if this is a bug report or a question.

Is it possible to dye a vest black after it has been dyed brown?
If so how?

If yes and Ive done it right its quite possibly broken.