| abstract |
Human air is dyed in successive treatments at selected intervals with oxidation colors (aromatic primary amines and aminophenols) admixed in each treatment with an oxidizing agent (H2O2 or a derivative thereof) - the quantity of oxidation colorant applied in each treatment being substantially the same and the quantity of oxidizing agent being increased from the first to the last treatment to effect a gradual increase in depth of shade - the mixture being allowed to remain on the hair for substantially the same tine in each treatment, followed by removal by rinsing. |