Quinone direct dye of formula below, organic or mineral acid or base salts thereof, tautomeric forms, optical isomers or geometrical isomers thereof and/or solvates thereof: in which formula: • n represents an integer equal to 0, 1, 2, 3 or 4; • R represents: - a linear or branched C 1 -C 4 alkyl radical; - a linear or branched C 1 -C 4 alkyl radical, substituted with one or more identical or different radicals chosen from hydroxyl and imidazolium radicals, An -; An - denoting a cosmetically acceptable anion or mixture of anions; - a C 1 -C 4 alkoxy radical; - a halogen atom; • R 1 represents: - a linear or branched C 1 -C 5 alkyl radical; - a linear or branched C 1 -C 5 alkyl radical, substituted with one or more hydroxyl radicals; • R 2 represents: - a linear or branched C 1 -C 5 alkyl radical; - a linear or branched C 1 -C 5 alkyl radical, substituted with one or more hydroxyl radicals; • X represents: - a hydroxyl radical; - a radical -NR 3 R 4 in which R 3 and R 4 represent, independently of each other: ▪ hydrogen atom; ▪ a linear or branched C 1 -C 6 alkyl radical; ▪ a linear or branched C 1 -C 6 alkyl radical, substituted with one or more hydroxyl or C 1 -C 4 alkoxy radicals. • n represents an integer equal to 0, 1, 2, 3 or 4; • R represents: - a linear or branched C 1 -C 4 alkyl radical; - a linear or branched C 1 -C 4 alkyl radical, substituted with one or more identical or different radicals chosen from hydroxyl and imidazolium radicals, An -; An - denoting a cosmetically acceptable anion or mixture of anions; - a C 1 -C 4 alkoxy radical; - a halogen atom; - a linear or branched C 1 -C 4 alkyl radical; - a linear or branched C 1 -C 4 alkyl radical, substituted with one or more identical or different radicals chosen from hydroxyl and imidazolium radicals, An -; An - denoting a cosmetically acceptable anion or mixture of anions; - a C 1 -C 4 alkoxy radical; - a halogen atom; • R 1 represents: - a linear or branched C 1 -C 5 alkyl radical; - a linear or branched C 1 -C 5 alkyl radical, substituted with one or more hydroxyl radicals; - a linear or branched C 1 -C 5 alkyl radical; - a linear or branched C 1 -C 5 alkyl radical, substituted with one or more hydroxyl radicals; • R 2 represents: - a linear or branched C 1 -C 5 alkyl radical; - a linear or branched C 1 -C 5 alkyl radical, substituted with one or more hydroxyl radicals; - a linear or branched C 1 -C 5 alkyl radical; - a linear or branched C 1 -C 5 alkyl radical, substituted with one or more hydroxyl radicals; • X represents: - a hydroxyl radical; - a radical -NR 3 R 4 in which R 3 and R 4 represent, independently of each other: ▪ hydrogen atom; ▪ a linear or branched C 1 -C 6 alkyl radical; ▪ a linear or branched C 1 -C 6 alkyl radical, substituted with one or more hydroxyl or C 1 -C 4 alkoxy radicals. - a hydroxyl radical; - a radical -NR 3 R 4 in which R 3 and R 4 represent, independently of each other: ▪ hydrogen atom; ▪ a linear or branched C 1 -C 6 alkyl radical; ▪ a linear or branched C 1 -C 6 alkyl radical, substituted with one or more hydroxyl or C 1 -C 4 alkoxy radicals. ▪ hydrogen atom; ▪ a linear or branched C 1 -C 6 alkyl radical; ▪ a linear or branched C 1 -C 6 alkyl radical, substituted with one or more hydroxyl or C 1 -C 4 alkoxy radicals.