Tinctorial composition for keratinous fibers, in particular for human hair, characterized in that it contains, in a medium appropriate for dyeing these fibers, at least one para oxidation dye precursor or at least one ortho oxidation dye precursor in combination with at least one heterocyclic coupler, corresponding to the formula: ##STR1## in which R.sub.1 denotes a hydrogen atom or a C.sub.1 -C.sub.4 alkyl radical; R.sub.2 denotes a hydrogen atom, a C.sub.1 -C.sub.4 lower alkyl radical, a carboxyl radical or an alkoxycarbonyl radical; R.sub.3 denotes a hydrogen or halogen atom, a C.sub.1 -C.sub.4 lower alkyl radical, a carboxyl radical, an alkoxycarbonyl radical or a formyl radical; X denotes a hydrogen atom, a C.sub.1 -C.sub.4 alkyl radical, a halogen atom, a C.sub.1 -C.sub.4 alkoxy radical, an acetylamino group or a dialkyl(C.sub.1 -C.sub.4)aminomethyl group; at least one of the groups X, R.sub.1, R.sub.2 and R.sub.3 differing from hydrogen; as well as their salts.