The invention relates to the use, for dyeing keratin fibres, of at least one latent pigment, which is soluble in a medium that is suitable for dyeing, and which can be chemically, thermally or photochemically converted in the fibres into water-insoluble pigments, of formula A(B)x with A representing the chromophoric radical of dyes, and B representing a hydrogen atom or a group of formula (II) with Z representing a cationic water-solubilizing group Z+ or a polyethylene glycol residue, Y representing a hetero atom, F and F′ representing a linear or branched C1-C14 alkylene chain, which may contain hetero atoms and may be substituted with one or more hydroxyl, amino or halogen groups. The invention also relates to processes for dyeing keratin fibres using latent pigments, to particular compositions containing them and to multi-compartment dyeing devices or “kits”.