TEINTURE DE FIBRES KERATINIQUES AU MOYEN D'UN PRETRAITEMENT FAISANT INTERVENIR UN SEL DE FER ET UN FIXATEUR DE COULEUR COMPRENANT UN TANIN HYDROLYSABLE
A method of colouring keratinous fibers comprising contacting the keratinousfibers sequentially with apre-treatment composition and a colour developer wherein : i. the pre-treatment composition comprises: (a) 0.5-25% by weight of an ironsalt at a pH below 2 including 0.5-5% by weight of a reducing agent (b) abuffer effective in the pH range 3-6 and (c) apenetration enhancer comprising one or more solvents having Hansen solubilityparameter .delta.h between 1-10 (MPa)1/2 and .delta.p between10-25 (MPa)1/2 wherein the component (b) is mixed with (a) or (c) not morethan 360 minutes prior to contacting the keratinousfibers and ii. the colour developer is selected from one or more ofhydrolysable tannin or its breakdown products or derivatives ora mixture thereof obtained from a natural or synthetic source, where thesequence of contact is in any order.
