The present invention is a method of pre-treating keratinous fibers prior to the application of a hair colorant or bleaching composition comprising the steps of applying a pre-treatment composition to the keratinous fibers said composition comprising at least one conditioning agent, said composition having a viscosity of from 100 Pa cps to 300 Pa, wherein said pre-treatment composition is not rinsed off from the hair prior to the application of said hair coloring or bleaching composition.