The invention relates to a composition comprising at least i) one coupler of formula (I),and also addition salts thereof, optical or geometrical isomers thereof, tautomers thereof or solvates thereof: in which formula (I): X represents a halogen atom, a COOH group or an amido group–C(O)–NR5R6 with R5 and R6, which may be identical or different, representing a hydrogen atom or an alkyl group, R1 to R4, which may be identical or different, represent a hydrogen or halogen atom, an alkyl group or an alkoxy group, and ii) at least one oxidation base. The invention also relates to a processfor dyeing keratin fibres using said composition.
