Coloring human keratin fibers e.g. hair, involves applying pretreatment composition, comprising alkaline metal carbonates and/or bicarbonates and aromatic alcohols, on keratin fibers and applying dye composition with natural dyes on fibers
Coloring human keratin fibers such as hair, comprises applying a pretreatment composition, comprising alkaline metal carbonates and/or alkaline metal bicarbonates and aromatic alcohols, on the keratin fibers, where the pretreatment composition has a pH value of less than 10, and applying a dye composition containing natural dyes on the keratin fibers. An independent claim is included for a multi-compartment device or kit for coloring comprising a first compartment comprising containing a pretreatment composition, a second compartment containing the dye composition, and optionally a third compartment containing a composition with metal salts.L'invention concerne un procédé de coloration des fibres kératiniques, telles que les fibres kératiniques humaines, et en particulier les cheveux, comprenant les étapes suivantes : - application sur les fibres kératiniques d'une composition de prétraitement comprenant un ou plusieurs carbonates de métaux alcalins et/ou bicarbonates de métaux alcalins, et un ou plusieurs alcools aromatiques, le pH de ladite composition de prétraitement étant inférieur à 10, puis - application sur les fibres kératiniques d'une composition colorante contenant un ou plusieurs colorants naturels.
