FIELD: cosmetology. SUBSTANCE: the present innovation deals with cosmetic composition for treating keratin fibers and, more concretely, hair, that contains in cosmetically acceptable medium: (i) at least, one oxidizing agent and (ii) at least, one certain aminosilicone, its application for dyeing, decolorization and constant deformation of human keratin fibers. The innovation, also, deals with the methods for either decolorization or dyeing, or constant deformation of human keratin fibers due to application of the above-mentioned composition. It provides prolonged conditioning action by not decreasing efficiency and homogeneity of constant deformation, dyeing or decolorization of human hair. EFFECT: higher efficiency. 33cl, 3 ex
