Use of a composition containing azo dyes indolylthiazolium for dyeing keratin fibers.

Use of a product containing at least one azo dye indolylthiazolium general formula (I) ** (See formula) ** wherein R1 represents a saturated or unsaturated alkyl group (C1-C12), an alkyl group (C1-C12) substituted with a halogen atom, a hydroxy- (C1-C12), a (C1-C6) alkoxy (C1-C12), aminoalkyl (C1-C12), a (C1-C6) alkylamino alkyl ( C1-C12), a (C1-C6) dialkylamino group (C1-C12) group, a cyano- (C 1-C 12), a substituted or unsubstituted phenyl group or a substituted benzyl group or unsubstituted; R2 and R3, identical or different, represent, independently of one another, hydrogen, a halogen atom, an alkyl group (C1-C12) saturated or unsaturated, alkoxy group (C1-C12), a nitro group, an amino group, an alkylamino group (C 1 -C 12) -alkylamino group, a (C 1-C 12), a hydroxyalkylamino group (C 1-C 12), a dihydroxyalkylamino group (C 1-C 12), a substituted or unsubstituted phenyl group or a substituted or unsubstituted heteroaryl group; R4 represents hydrogen, an alkyl group (C 1-C 12) saturated or unsaturated, an alkyl group (C 1-C 12) substituted with a halogen atom, a hydroxy- (C1-C12), alkoxy (C1-C6 ) (C1-C12), aminoalkyl (C1-C12) alkylamino (C1-C6) alkyl (C1-C12), a (C1-C6) dialkylamino group (C1-C12) group, a cyano- (C1-C12), substituted or unsubstituted phenyl group, a substituted or unsubstituted benzyl group or a substituted or unsubstituted heteroaryl group; R5, R6, R7 and R8, identical or different, represent, independently of one another, hydrogen, a halogen atom, an alkyl group (C1-C12) saturated or unsaturated, a hydroxyl group, an alkoxy group (C1-C12), a nitro group, an amino group, a (C1-C12) alkylamino group or a (C1-C12) dialkylamino group; and A- is an anion of an organic or inorganic acid. For dyeing keratin fibers.