Ochre
Ground ochre is pigmented clay found in the earth. It is a mixture of ferric oxide with mixtures of clay and sand. It ranges in color from yellow to deep orange or brown.
In Africa, red ochre is said to have been used for 200,000 years. One excellent example of its use is among the people of the Himba Tribe in Namibia.
Their hair is often dreadlocked with a mixture of ground ochre, goat hair and butter.
If you don’t wish to use it in this particular way, you could apply it as hair treatment as is the case with Aztec bentonite clay.