Provided is a hair dye composition containing a dissociative direct dye represented by the following formula (1): wherein, R1 to R4 each represents H or substituent, X represents OH or -NHSO2R5, R5 represents an alkyl, aryl or heterocyclic group, and A represents a divalent group capable of forming a methine dye as a whole compound, together with the portion other than A.The hair dye composition of the present invention is capable of strongly dyeing the hair with a vivid color tone without causing decomposition of the dye during the dyeing process, exhibits an excellent resistance against sunlight, hair washing, perspiration, friction and heat, has a high stability against an alkali agent and an oxidizing agent, has a high dyeing property, and has less color fade after the passage of time.