The present invention provides a dyeing composition comprising, in a cosmetically acceptable medium, one or more oxidation dyes, aqueous ammonia, ammonium chloride and one or more additives selected from ceramides, silicas, ascorbic acid and/or its salts, fatty acids and/or salts thereof, alkanolamines and/or salts thereof, crosslinked homopolymers of acrylic acid, copolymers of dialkyldiallylammonium chloride and acrylic acid, and particular cationic polymers, or mixtures thereof. It likewise provides a method of colouring human keratin fibres, employing the said composition in the presence of a composition comprising one or more oxidizing agents. The invention further provides a multiple-compartment device appropriate to the implementation of the said method, comprising in a first compartment a dyeing composition according to the invention and in another compartment a composition comprising one or more oxidizing agents.