The invention relates to 4-aminoindole derivatives of formula (I), and the addition salts thereof, mesomers thereof, isomers thereof and solvates thereof: and to their use for the oxidation dyeing of keratin fibres, and in particular of human keratin fibres such as the hair. The present invention makes it possible to achieve dark shades, natural shades and dark natural shades. The present invention also makes it possible to obtain powerful, chromatic, aesthetic, sparingly selective coloration of keratin fibres in varied shades, which is resistant to the various attacking factors to which the hair may be subjected. In particular, when the 4-aminoindole derivatives are combined with one or more heterocyclic oxidation bases, they make it possible to obtain a wide range of colours and coloration of keratin fibres that shows good chromaticity and good selectivity.