| abstract |
(57) [Problem] To provide a hair dye composition which does not cause coloring of the scalp or skin, has excellent dyeing properties on hair, and does not generate gas due to hydrolysis in an acidic region. SOLUTION: The following components (A) and (B) (A) acid dye (B) containing a compound having a 5- or 6-membered lactone skeleton and having a pH of 2 to 6, and 10 times diluted aqueous solution. A hair dye composition having a buffer capacity of 0.004 gram equivalent / L or more and less than 0.2 gram equivalent / L. |