The present invention addresses the problem of providing a disinfectant solution that is prepared by coloring an aqueous olanexidine gluconate solution, said solution being a colorless and transparent liquid, and, therefore, can facilitate the confirmation of an area to which the disinfectant solution is applied for preoperative disinfection etc. A disinfectant solution capable of facilitating the confirmation of an area to which the disinfectant solution is applied for preoperative disinfection etc., can be prepared by using olanexidine gluconate, a coloring agent such as Sunset Yellow FCF and an alkyldimethylamine oxide such as lauryldimethylamine oxide, optionally together with one or more kinds of surfactants other than alkyldimethylamine oxides, for example, a polyoxyethylene alkyl ether such as lauromacrogol and a polyoxyethylene polyoxypropylene alkyl ether such as polyoxyethylene(20) polyoxypropylene(4) cetyl ether.本發明的課題在於提供一種消毒液，將無色透明液體的奧蘭西丁葡萄糖酸鹽（Olanexidine gluconate）的水溶液著色，在手術前的皮膚消毒等容易確認塗佈部位。藉由包含奧蘭西丁葡萄糖酸鹽、日落黃FCF等著色料、月桂基二甲基氧化胺等烷基二甲基氧化胺、任意的聚桂醇等的聚氧乙烯烷基醚或聚氧乙烯（20）聚氧丙烯（4）十六烷基醚等的聚氧乙烯聚氧丙烯烷基醚等、烷基二甲基氧化胺以外的一種或兩種以上的界面活性劑，可製作在手術前的皮膚消毒等，容易確認塗佈部位的消毒液。
