Method for producing a shading on the hair, comprising the stage consisting in: subjecting an amount of a composition (100) capable of exhibiting a variation in its hair dyeing or bleaching power under the effect of a chemical and/or energy stimulus to the said stimulus, so as to obtain at least two fractions (1000; 2000) of the said amount each having a hair dyeing or bleaching power distinct from that of the other fraction, the composition (100) being subjected to the stimulus before or after it is brought into contact with the hair and the composition producing, after exposure to the said stimulus and being brought into contact with the hair, a shaded dyeing or bleaching.