One of the most popular methods for centuries has been the use of henna for hair colour.
I still use the powder I buy from the Indian Spice Shop. Leaves your hair healthy and shiny.
Henna is ground the plant. These stones have been used for a few hundred years, donkeys were originally used to push the stone wheel until the 1940s when electric motors were installed. Most of this henna is used in Iran and India. I like to think that I am buying some of this from the Indian Spice Shop.