A hair treatment composition, particularly a hair colouring and/or bleaching composition, comprising an oxidizing agent, an alkalizing agent selected from the group consisting of ammonia, its salts and mixtures thereof, one or more fatty alcohol(s), one or more non-ionic surfactant(s) and a specific fatty compound. It is also provided a kit, method and use thereof. Superior hair treatment performance, particularly superior colouring and bleaching performance, with a reduced or an eliminated smell of said alkalizing agent upon application, is achieved.
