A two-part hair dye including a first part containing an alkali agent, a second part containing hydrogen peroxide, and a non-aerosol foamer vessel to discharge in the form of foam a liquid mixture of the first part and the second part, wherein the liquid mixture contains anionic surfactant(s) selected from the following components (A1) to (A3), or the following components (A4) and (A5): (A1) a carboxylate type anionic surfactant； (A2) a sulfonate type anionic surfactant； (A3) a phosphate type anionic surfactant； (A4) an ionic surfactant； and (A5) a fatty acid alkanolamide.一種二劑式染毛劑，其係由含有鹼劑之第1劑、含有過氧化氫之第2劑、以及用以將第1劑與第2劑之混合液以泡狀噴出之非氣溶膠發泡容器所構成，混合液中含有選自以下成分(A1)~(A3)中之陰離子界面活性、或以下成分(A4)及(A5)：(A1)羧酸系陰離子界面活性劑；(A2)磺酸系陰離子界面活性劑；(A3)磷酸酯系陰離子界面活性劑；(A4)離子性界面活性劑；(A5)脂肪酸烷醇醯胺。
