A method of reducing and/or preventing the bleaching and/or fading of artificially produced hair colors, includes the following steps: i. applying a cosmetic composition to the preferably wet, colored hair, ii. allowing the composition to act for a period of at least 5 s, iii. optionally: rinsing the composition out with water. The cosmetic composition, based on the weight thereof, includes a) 0.05 to 0.5 mol/kg of at least one divalent salt of a monobasic organic acid or b) 0.01 to 0.5 mol/kg of at least one monobasic organic acid (b1) and 0.05 to 0.5 mol/kg of at least one divalent inorganic salt (b2), and the cosmetic composition has a pH in the range from 4.0 to 4.8.
