A hair dye that is safe for human bodies and has a high hair dyeing effect is provided.
The hair dye consisting of: a reaction solution (A) comprising: a substance having a specific flavonoid skeleton represented by the following general formula (1); one type or two or more types selected from benzyl alcohol, vanillin, propylene carbonate, and γ-butyrolactone; and one type or two or more types selected from a thioglycolic acid salt, a thiolactic acid salt, cysteine and cysteamine, and a reaction solution (B) comprising an oxidizing agent. (In the formula, R1, R2, R3, R4, R6, and R7 independently represent a hydrogen atom, a hydroxy group, or a methyl group; either one or both of R6 and R7 is/are a hydroxy group; R5 represents a hydrogen atom, a hydroxy group, a galloyl group, or a saccharide; and X represents >CH2, >C═O, or >CHOH.)