A first agent for oxidative hair dye of the present disclosure includes: an (A) component, which is at least one selected from the group consisting of resorcin, derivatives thereof, and salts thereof, in a content not exceeding 0.15% by mass； a (B) component, which is a coupler such as m-aminophenol, a (C) component, which is a dye intermediate such as p-phenylenediamine in a content between 0.01% by mass and 0.45% by mass； and a (D) component, which is an alkanolamine.本發明提供一種在氧化染髮劑第一劑中包含烷醇胺的構成中能夠提高染料的穩定性的氧化染髮劑第一劑以及氧化染髮劑組成物的色調穩定化方法。本發明的氧化染髮劑第一劑含有下述(A)～(D)成分：(A)不大於0.15質量%的量的選自間苯二酚及其衍生物、以及它們的鹽中的至少一種；(B)間胺基苯酚等偶聯劑；(C)0.01質量%～0.45質量%的對苯二胺等染料中間體；以及(D)烷醇胺。
