A hair dye composition containing a triazene dissociative direct dye represented by general formula (1): A—N=N—NH—B (1) wherein A and B are each a monocyclic or a bicyclic aromatic heterocyclic group that may have a substituent or a monocyclic or a bicyclic aryl group that may have a substituent and contain none of a carboxy group, a sulfo group and a quaternary ammonium group; and A and B each bind to a triazene-1,3-diyl group represented by —N=N—NH— via a carbon atom within A and B each. A and B may be the same or different.