Table 1. Category and Composition of Modern Hair Dyes.

dye category	hair coloring process	composition	hair dyeing type
temporary	nonoxidative	water-soluble acidic and basic dyes bearing azo or anthraquinone groups	deposition on hair
semipermanent	nonoxidative	acid and basic dyes bearing azo groups, anthraquinones, triphenylmethanes and nitro derivatives as chromophores	ionic interactions or van der Waals forces
permanent	oxidative	precursor agent, coupling agent and oxidizer	penetration into hair