| abstract |
Agents for dyeing keratin fibers, in particular human hair, which clearly indicate the time of optimal mixing of dyeing composition and oxidizing agent preparation are prepared prior to use by mixing at least one dyeing composition containing at least one dye precursor and at least one developing composition containing at least one oxidizing agent the developer composition comprises at least one pH indicator selected from dimethyl yellow, Congo red, bromophenol blue, bromochlorophenol blue, methyl orange, α-naphthyl red, bromocresol green, mixed indicator 5, methyl red, ethyl red, chlorophenol red, carminic acid, alizarin red S, litmus, bromocresol purple, bromophenol red, alizarin, bromothymol blue, Bromoxylenol blue, brazilin, nitrazing yellow, hematoxylin, phenol red, neutral red, cresol red, m- cresol purple, brilliant yellow, orange I, α-naphtholphthalein, thymol blue, p-xylenol blue, cresolphthalein, phenolphthalein, blue Nile A (sulfa t), α-naphtholbenzein, thymolphthalein, water-blue. |