A two-part hair dye including a first part containing an alkali agent, a second part containing hydrogen peroxide, and a non-aerosol foamer container； wherein a liquid mixture contains Components (A) and (B) specified below, wherein the content of hydrogen peroxide in the liquid mixture is 3.60 mass% or higher, and the viscosity of the liquid mixture is 1 to 300 mPa·s. A method for dying hair, wherein a foam of the liquid mixture of the first part and the second part of the two-part hair dye is applied to hair, left to stand for 3 to 60 minutes, and then washed out. Component (A): oxidation dye； Component (B): 0.50 to 3.0 mass% of polypropylene glycol having a weight-average molecular weight of 200 to 800.本發明提供一種二劑式染毛劑及毛髮之染色方法。本發明之二劑式染毛劑包含：含有鹼劑之第1劑、含有過氧化氫之第2劑、及非氣溶膠發泡容器；並且於混合液中含有以下之成分(A)及(B)，過氧化氫於混合液中之含量為3.60質量%以上，混合液之黏度為1~300 mPa‧s。本發明之毛髮之染色方法係將該二劑式染毛劑之第1劑與第2劑之混合液之泡應用於毛髮，放置3~60分鐘後進行沖洗。成分(A)：氧化染料成分(B)：重量平均分子量為200~800之聚丙二醇0.50~3.0質量%
