A hair dye composition comprising at least one oxidation dye and at least one diphenylamine of the formula ##STR1## wherein R.sub.1 and R.sub.4 each independently represent hydrogen, halogen, lower alkyl having 1-6 carbon atoms, lower alkoxy having 1-6 carbon atoms, acylamino or ureido;R.sub.2 and R.sub.3 each independently represent hydrogen, halogen, lower alkyl having 1-6 carbon atoms, lower alkoxy having 1-6 carbon atoms, amino, N-alkylamino wherein the alkyl has 1-6 carbon atoms, N-hydroxyalkylamino wherein the alkyl has 1-6 carbon atoms, acylamino, N-carbamylalkylamino wherein the alkyl has 1-6 carbon atoms or ureido;R.sub.5 represents hydrogen, halogen, lower alkyl having 1-6 carbon atoms or lower alkoxy having 1-6 carbon atoms;R.sub.6, R.sub.7 and R.sub.8, each independently represent hydrogen, halogen, lower alkyl having 1-6 carbon atoms or lower alkoxy having 1-6 carbon atoms;Y represents hydroxy or amino; andZ represents hydroxy or ##STR2## wherein R.sub.9 and R.sub.10 each independently represents hydrogen, lower alkyl containing 1-6 carbon atoms, hydroxyalkyl containing 1-6 carbon atoms, carbamyl alkyl wherein the alkyl has 1-6 carbon atoms, amino alkyl wherein the alkyl has 1-6 carbon atoms, monoalkylamino alkyl wherein each alkyl has 1-6 carbon atoms, dialkylamino alkyl wherein each alkyl has 1-6 carbon atoms, acylaminoalkyl wherein the alkyl has 1-6 carbon atoms, alkylsulfonamido alkyl wherein each alkyl has 1-6 carbon atoms, arylsulfonamidoalkyl wherein the alkyl has 1-6 carbon atoms, sulfoalkyl wherein the alkyl has 1-6 carbon atoms, piperidinoalkyl wherein the alkyl has 1-6 carbon atoms or morpholinoalkyl wherein the alkyl has 1-6 carbon atoms; ora salt thereof.