Two-stage process for dyeing keratin fibres

摘要

A two-stage process for dyeing keratin fibres, especially human hair, is described which involves treating the fibres with a first composition at a first pH and subsequently, without rinsing treating the fibres with a second composition at a second pH, at least one of the compositions containing a dyestuff for the fibres, and the second pH being different from the first pH so as to modify the effect of at least one active ingredient on the fibres.