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 À bond, R 1 : OH or acetoxy, R 2 : H, -COOR (R: H, CH 3 or C 2 H 5 ) or -COO - X + (X + : cation), and R 3 : H, acetyl, CH 3 or C 2 H 5 ).本發明的一劑式染毛劑組成物,係含有下述(A)~(D),且pH8~11。(A):式(1)所示化合物之1種或2種以上。(B):抗壞血酸或其鹽、與亞硫酸或其鹽的組合之抗氧化劑。(C):非離子界面活性劑。(D):增黏聚合物。藉由調整成分(B)中的(抗壞血酸或其鹽)/(亞硫酸或其鹽)之重量比,而調整經染毛後所獲得色調的方法。〔式中,虛線係指有存在或未存在π鍵;R1係指OH或乙醯氧基;R2係指H、-COOR(R係H、CH3或C2H5)、或-COO-X+(X+係陽離子);R3係指氫原子、乙醯基、CH3或C2H5〕。
