Method for dyeing human keratin fibres, characterized in that one applies to the fibres a dyeing composition comprising, in an appropriate cosmetic medium, at least one disulfide dye chosen from the dyes of the following formulae,, or: A- p - C sat - S-S - C sat - p - A A- p - C sat - S-S - C sat - p - D their salts or solvates such as hydrates, in which formulae: • A and A', which are identical or different, represent a radical containing at least one chromophore derived from cyanine-type dyes, said chromophores A and/or A' contain a cationic radical borne by or included in at least one of the chromophores; said cationic radical B is quaternary ammonium; • V and V', which are identical or different, represent a bridging group; • v and v', which are identical or different, represent 0 or 1; • X, which are identical or different, represent a saturated or unsaturated, linear or branched C 1 -C 30 hydrocarbon chain optionally interrupted and/or optionally terminated at one or both of its ends by one or more divalent groups or combinations thereof, chosen from: - -N -, -N + -, -O-, -S-, -CO-, -SO 2 - with R, which are identical or different, being chosen from hydrogen, a C 1 -C 4 alkyl, hydroxyalkyl or aminoalkyl radical; - an optionally substituted, saturated or unsaturated, fused or nonfused, aromatic or nonaromatic (hetero) cyclic radical optionally comprising one or more identical or different heteroatoms; • the coefficient p is equal to 0 or 1; • C sat, C' sat, which are identical or different, represent an optionally substituted, optionally cyclic, linear or branched C 1 -C 18 alkylene chain; • D corresponds to a radical chosen from hydroxyl, hydroxyalkyl, alkoxy, carboxyl, carboxylate, amino, alkylamino and dialkylamino radicals. • A and A', which are identical or different, represent a radical containing at least one chromophore derived from cyanine-type dyes, said chromophores A and/or A' contain a cationic radical borne by or included in at least one of the chromophores; said cationic radical B is quaternary ammonium; • V and V', which are identical or different, represent a bridging group; • v and v', which are identical or different, represent 0 or 1; • X, which are identical or different, represent a saturated or unsaturated, linear or branched C 1 -C 30 hydrocarbon chain optionally interrupted and/or optionally terminated at one or both of its ends by one or more divalent groups or combinations thereof, chosen from: - -N -, -N + -, -O-, -S-, -CO-, -SO 2 - with R, which are identical or different, being chosen from hydrogen, a C 1 -C 4 alkyl, hydroxyalkyl or aminoalkyl radical; - an optionally substituted, saturated or unsaturated, fused or nonfused, aromatic or nonaromatic (hetero) cyclic radical optionally comprising one or more identical or different heteroatoms; - -N -, -N + -, -O-, -S-, -CO-, -SO 2 - with R, which are identical or different, being chosen from hydrogen, a C 1 -C 4 alkyl, hydroxyalkyl or aminoalkyl radical; - an optionally substituted, saturated or unsaturated, fused or nonfused, aromatic or nonaromatic (hetero) cyclic radical optionally comprising one or more identical or different heteroatoms; • the coefficient p is equal to 0 or 1; • C sat, C' sat, which are identical or different, represent an optionally substituted, optionally cyclic, linear or branched C 1 -C 18 alkylene chain; • D corresponds to a radical chosen from hydroxyl, hydroxyalkyl, alkoxy, carboxyl, carboxylate, amino, alkylamino and dialkylamino radicals.