Abstract: The present invention relates to a process for the oxidation dyeing of keratin fibers implementing: a) a step of pretreating said fibers by application to said fibers of a cosmetic composition (B) comprising: i) at least one fatty substance in an amount of greater than or equal to 10% by weight relative to the total weight of the composition (B); and ii) at least one metal catalyst; b) optionally a washing, rinsing, drying and/or rubbing-dry step; c) followed by a step of dyeing by application to said fibers of a cosmetic composition (A) comprising: i) at least one oxidation base, preferably chosen from para-phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, ortho-aminophenols, heterocyclic bases preferably comprising at least two nitrogen atoms, and addition salts thereof; ii) optionally at least one coupler; and iii) at least one chemical oxidizing agent.

Abstract: The present invention relates to a process for the oxidation dyeing of keratin fibres implementing: a) a step of pretreating said fibres by application to said fibres of a cosmetic composition (B) comprising: i) at least one fatty substance in an amount of greater than or equal to 10% by weight relative to the total weight of the composition (B); and ii) at least one metal catalyst; b) optionally a washing, rinsing, drying and/or rubbing-dry step; c) followed by a step of dyeing by application to said fibres of a cosmetic composition (A) comprising: i) at least one oxidation base, preferably chosen from para-phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, ortho-aminophenols, heterocyclic bases preferably comprising at least two nitrogen atoms, and addition salts thereof; ii) optionally at least one coupler; and iii) at least one chemical oxidizing agent.