The subject of the present invention is a composition for staining human keratinous fibers comprising, in a cosmetically acceptable medium: a compound of the family of iridoids of formula (I) below, or a plant extract comprising: Where R: hydrogen, methyl hydroxymethyl, aldehyde; -CO R wherein R: hydrogen, C 1 -C 6 alkyl; sugar; R: a hydrogen atom, a hydroxyl radical, a sugar radical; R 1: hydrogen, hydroxyl, alkyloxy; R: sugar radical (aldose or derivative); integer ranging from 1 to 5; the compound or compounds of formula (I) having optionally undergone a preliminary step of replacing the radical R with a hydrogen atom produced by means of an enzyme; at least one aldehyde or imine compound of formulas (i) and (ii), as well as the oxidized oligo- or polysaccharides comprising at least one aldehyde or imine function: ## EQU1 ## With n equal to 0 or 1; X: O, NR'1; A: COOH, optionally substituted aryl, 5- or 6-membered heterocycle, cationic or non-cationic, unsaturated or unsaturated, comprising one or two heteroatoms, optionally substituted, alkyl, alkenyl; A2 divalent alkylene; the compounds which may be in the case of aldehydes, in the form of acetal or hemiacetal. It also relates to a process using such a composition as well as devices with several compartmentsLa présente invention a pour objet une composition de coloration de fibres kératiniques humaines comprenant, dans un milieu cosmétiquement acceptable : * un composé de la famille des iridoïdes de formule (I) suivantes, ou un extrait végétal en comprenant : Où R : hydrogène, méthyle, hydroxyméthyle, aldéhyde ;-CO R dans lequel R : hydrogène, alkyle en C -C ; sucre ; R : un atome d'hydrogène, un radical hydroxyle, un radical sucre ; R , : hydrogène, hydroxyle, alkyloxy ; R : radical sucre (aldose ou dérivé) ; entier variant de 1 à 5 ; le ou les composés de formule (I) ayant éventuellement subi une étape préalable consistant à remplacer le radical R par un atome d'hydrogène réalisée au moyen d'une enzyme; ** au