Abstract: Provided is a one-part hair dye composition containing (A) one or two or more compounds represented by the formula (1), (B) an antioxidant composed of a combination of ascorbic acid or salt thereof and sulfurous acid or salt thereof, (C) a nonionic surfactant, and (D) a thickening polymer; and having a pH of from 8 to 11; and a method of controlling hair color by adjusting an (ascorbic acid or salt thereof)/(sulfurous acid or salt thereof) weight ratio in Component (B) of the composition: (wherein, a broken line: the presence or absence of a ? bond, R1: OH or acetoxy, R2: H, —COOR (R: H, CH3 or C2H5) or —COO?X+ (X+: cation), and R3: H, acetyl, CH3 or C2H5).

Abstract: Provided are a one-part hair dye composition containing (A) a combination of 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, (B) either one of (b1) ascorbic acid or salt thereof or (b2) sulfurous acid or salt thereof, and (C) an alkali agent and having a pH of from 8 to 11; and a method of selecting the kind of Component (B), thereby controlling a hair color upon dyeing the hair.

Abstract: A one-part hair dye composition containing (A) one or more compounds represented by the formula (1), (B) a silicone, and (C) a polyol, wherein the composition has a pH of from 8 to 11, wherein, a broken line represents the presence or absence of ? bond, R1 represents OH or acetoxy, R2 represents H, —COOR (R representing H, CH3 or C2H5) or —COO?X+ (X+ representing a cation), and R3 represents H, acetyl, CH3 or C2H5.

Abstract: Provided are a one-part hair dye composition containing (A) a combination of 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, (B) either one of (b1) ascorbic acid or salt thereof or (b2) sulfurous acid or salt thereof, and (C) an alkali agent and having a pH of from 8 to 11; and a method of selecting the kind of Component (B), thereby controlling a hair color upon dyeing the hair.

Abstract: Provided is a one-part hair dye composition containing (A) one or two or more compounds represented by the formula (1), (B) an antioxidant composed of a combination of ascorbic acid or salt thereof and sulfurous acid or salt thereof, (C) a nonionic surfactant, and (D) a thickening polymer; and having a pH of from 8 to 11; and a method of controlling hair color by adjusting an (ascorbic acid or salt thereof)/(sulfurous acid or salt thereof) weight ratio in Component (B) of the composition: (wherein, a broken line: the presence or absence of a ? bond, R1: OH or acetoxy, R2: H, —COOR (R: H, CH3 or C2H5) or —COO?X+ (X+: cation), and R3: H, acetyl, CH3 or C2H5).

Abstract: A one-part hair dye composition containing (A) one or more compounds represented by the formula (1), (B) a silicone, and (C) a polyol, wherein the composition has a pH of from 8 to 11, wherein, a broken line represents the presence or absence of ? bond, R1 represents OH or acetoxy, R2 represents H, —COOR (R representing H, CH3 or C2H5) or —COO?X+ (X+ representing a cation), and R3 represents H, acetyl, CH3 or C2H5.