The Himba don't wash their hair as you might imagine shampooing your hair. Due to the scarcity of water, instead they'll use wood ash to cleanse their hair. Similarly, instead of bathing they'll cover themselves in otjize paste, which is a mixture of butterfat and ochre pigment.
The paste cleanses their skin and also protects them from the sun and mosquito bites. Due to the ochre mixed in, their skin and hair will have a reddish or deep orange tinge to it. The braided hair covered in otjize is a pretty unique look as far as I'm concerned.