Composition comprises, in a medium, substituted iridoid compounds (I) and/or 2,5-dihydro-furan-2-ol compounds (IA) or their plant extracts, and at least one nucleophilic carbonyl compound, which optionally comprises anions or their mixtures to ensure electrical neutrality of the composition. Composition comprises, in a medium, substituted iridoid compounds of formula (I) and/or 2,5-dihydro-furan-2-ol compounds of formula (IA) or their optical or geometrical isomers, or their mineral or organic acid salts, or solvates, or their plant extracts, where (I) optionally undergo a step comprising replacing the radical R with a hydrogen atom produced by an enzyme, prior to or simultaneously during the coloring of hair, and at least one nucleophilic carbonyl compound of formula (A1-C(=O)-C((R1b) 2)-C(=O)-B1) (II), (III), (IV) or (R25-O-C(=O)-CH 2-CN) (V) or its optical or geometrical isomer, organic or mineral acid salt or solvate, where the compounds (II)-(V) optionally comprise anions or their mixtures to ensure electrical neutrality of the composition, and are also from carbonyl oligomers or polymers comprising polymalonic acids or their esters, polysuccinic acids and/or sulfoacetic acid polymers. R1 : hydroxymethyl, -CO 2R4 or a sugar radical； R4 : H or 1-2C-alkyl； R2 : H, hydroxy or a sugar radical； R3 : H, hydroxy or 1-4C-alkyloxy, where the number of hydroxy groups is = 2； R : a sugar radical, where the sugar radical is a derivative obtained from an aldose or its derivative； n : 1-5； either A1 : A11-[C((R1a) 2)-C((R1a) 2)] n1-, A11a-[C(R1a)=C(R1a)] n1- or A22-O-； and B1 : B11-[C((R1a) 2)-C((R1a) 2)] m1-, B11a-[C(R1a)=C(R1a)] m1- or B22-O-； or A1+B1 : a 5- or 6-membered ring or heterocycle optionally comprising a heteroatom, preferably O, where the ring or heterocycle is optionally fused to a phenyl radical i.e. optionally substituted with at least one CH 3CO-, -COOR66 or -OCOR66； n1 : 0 or 1； m1 : 0 or 1； R1a : H or 1-4C-alkyl； either R1b : H or CH 3CO-, where one of t
