The present invention relates to a composition for dyeing human keratin fibres such as the hair, comprising: (a) one or more amphoteric surfactants at a concentration of at least 0.5% by weight relative to the total weight of the composition; (b) one or more organic alkaline agents; (c) one or more oxidizing agents; (d) one or more oxidation dye precursors; (e) an amount of ammonia of less than 1.5% by weight relative to the total weight of the composition; (f) one or more cationic polymers. The invention also relates to a process for treating human keratin fibres using this composition, and aerosol or nonaerosol devices that make it possible to apply this composition in foam form.