The present invention relates to the field of dyeing keratin fibers and more particularly to the field of hair dyeing. The present invention relates to a process for the oxidation dyeing of keratin fibers, in particular human keratin fibers such as the hair, which consists in using on the said fibers i) a substrate comprising on its surface one or more oxidation dyes, and ii) an aqueous composition comprising one or more oxidizing agents. The present invention also relates to a process for preparing the said substrate thus pretreated.
