Indigo powder is a natural plant based dye that's used to coloring hair, treat dandruff, and promote hair growth. It's made from the leaves of the Indigofera tinctoria plant. Indigo powder used in hair care to achieve a deep, black color when mixed with henna or applied on its own. As a safe and chemical-free alternative to synthetic hair dyes, indigo powder is an excellent choice for those looking for a more natural way to color their hair.