I have been interested in natural dyes for a long time. I finally got a chance to experiment with black walnut producing khaki brown green colors.

Here is a good resource on it:
http://www.practicalprimitive.com/skillofthemonth/blackwalnutdye.html

Someday I would love to produce blue or indigo ( there is a professor at IU that specializes in it):
http://www.indigrowingblue.com/index.html

http://www.rickettsindigo.com/
http://homepages.indiana.edu/web/page/normal/13665.html

For now I will have to keep my eyes open.

P.S. How do materials and the process matter for us?
P.S.S. Experiment with turmeric.