Patent ID: 7241319

Claim:
A dye composition for dyeing human keratin fibers comprising: a medium suitable for dyeing human keratin fibers, wherein said medium is water or a mixture of water and at least one organic solvent suitable for dyeing human keratin fibers, and at least one direct polycationic dye of formula (I) below, comprised in said medium: Col-Z-Col (I) in which Col, which may be identical or different, is a noncationic dye chosen from azo, methine, azomethine, phenothiazine, triarylmethane, xanthene phenanthridine, and phthalocyanin dyes; and Z is chosen from linear and branched, saturated and unsaturated, and cyclic C 1 -C 20 hydrocarbon-based groups comprising at least one nitrogen atom and bearing at least two cationic charges, and at least one cosmetic adjuvant chosen from monoalcohols, polyols, anionic, cationic, nonionic, amphoteric and zwitterionic surfactants, and mixtures thereof, mineral thickeners, organic thickeners, and anionic, cationic, nonionic and amphoteric associative polymers.