A method for straightening and dyeing keratinous fibers includes the following steps: A) treating the fibers with a straightening agent (G), B) treating the fibers with a conditioner (K), and C) treating the fibers with a coloring agent (F). The straightening composition (G) includes at least one alkalizing agent selected from sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, and/or guanidinium hydroxide, the conditioner (K) and/or the coloring agent (F) include(s) at least one reducing agent selected from thiolactic acid, thioglycolic acid, cysteine, sodium sulfide, sodium sulfite, sodium thiosulfate, sodium dithionite, and/or cosmetically acceptable salts thereof, and the coloring agent (F) includes at least one direct acid dye.
