New chloro-meta-phenylenediamines, their use as couplers in the oxidation dyeing of keratinous fibres, dyeing compositions for hair containing these compounds and dyeing process using the said compositions.The invention relates to the compounds of formula: ##STR1## in which Z and Z' denote, independently of one another, an alkyl radical having from 1 to 4 carbon atoms or a hydroxyalkyl radical having from 2 to 4 carbon atoms, andR.sub.1 and R.sub.2 denote, independently of one another, a hydrogen atom, an alkyl radical having from 1 to 4 carbon atoms or a mono- or polyhydroxyalkyl radical having 2 or 3 carbon atoms, to their addition salts with an acid, and to their use by way of couplers for the oxidation dyeing of keratinous fibres, especially human hair.These compounds, when they are combined with paraphenylenediamines, surprisingly give beige to light brown hues or purple hues of greater or lesser redness, depending on the substitution of the 5-amino group of the chlorobenzene.