I hulled the walnuts that are ready and thought it would be a great opportunity to try dying with the hulls. I filled a pot about 1/4 full with the hulls and added water and boiled it for about 1 1/2 hours. because I couldn't find a good way to strain it I cut a pair of stockings in half and put a skein of yarn in each half and tied it shut.
I just popped these in the pot and left for an hour ( I turned the heat off). The first lot was quite dark. The next lot I did not leave in as long.