Green husks are very easy to use for a deep brown dye! You can use it as paint or dye for paper and textile.
Step 1: Collecting, Drying and Crumbling Green Husks
Green husks are the green shells around walnuts. The best time to get the green husks is in September. Then the husks will shrivel, turn black and fall of the tree. After collecting them, you have to dry them by spreading them on a sheet and put it on the heater.
After drying the husks you can crumble them easily. On the last photo you see three steps of crumbling. The second step is good enough to get a brown color!
Step 2: Boiling
How longer you boil the water with the pieces of the green husk, the darker the color gets. Click on the last photo to see how long I boiled it to get the specific color. If you want to dye a piece of textile, you can boil it together with the water and pieces green husk.