The present specification discloses a agent composition for modifying a pigment to dye that imparts tinting strength to the pigment, and a colorant composition in which a pigment is modified to dye using the same. According to the present disclosure, since the pigment has tinting strength on the skin, it is possible to realize various colors of the pigment as it is while having excellent durability when applied to the skin. Accordingly, the pigment may be comprised as a coloring agent in a cosmetic formulation requiring coloring by replacing the dye having a limitation in type and color when used in a cosmetic composition due to a stability problem for the skin. In addition, since the coloring agent according to the present disclosure has an irreversibly stabilized form, it can be widely used without being limited to the pH, formulation, etc. of the cosmetic composition.

Provided are a dyeing composition which contains an azo coloring agent represented by Formula 1 or 2, a dyed product which is obtained by being dyed with the dyeing composition, and a novel azo coloring agent. In Formulae 1 and 2, C.sup.1 represents a heteroaromatic group, A.sup.1 and B.sup.1 each independently represent a heteroaromatic group, an aromatic group, or a group having a methine structure, and at least one of A.sup.1 or B.sup.1 represents a heteroaromatic group, D.sup.1 represents an anthraquinonyl group, and E.sup.1 represents a heteroaromatic group, an aromatic group, or a group having a methine structure.

A.sup.1-NNC.sup.1NNB.sup.1Formula 1

D.sup.1-NN-E.sup.1Formula 2

Naphthol AS-pigments of formula (I), wherein R1 represents methyl or C3-C8-alkyl; R2 represents hydrogen or C1-C4-alkyl; Y represents C1-C4-alkyl or C1-C4-alkoxy; and Z represents hydrogen, phenyl, naphthyl, or substituted phenyl or substituted naphthyl, wherein the number of substituents can be 1, 2, 3 or 4 and are selected from the group consisting of halogen, nitro, cyano, C1-C4-alkoxycarbonyl, carbamoyl, C1-C4-alkylcarbamoyl, di(C1-C4)-alkylcarbamoyl, phenylcarbamoyl, sulfamoyl, phenylsulfannoyl, C1-C4-alkylsulfamoyl, di(C1-C4)-alkylsulfamoyl, C1-C4-acylamino, C1-C4-alkyl and C1-C4-alkoxy.

Naphthol AS-pigments of formula (I), wherein R1 represents methyl or C3-C8-alkyl; R2 represents hydrogen or C1-C4-alkyl; Y represents C1-C4-alkyl or C1-C4-alkoxy; and Z represents hydrogen, phenyl, naphthyl, or substituted phenyl or substituted naphthyl, wherein the number of substituents can be 1, 2, 3 or 4 and are selected from the group consisting of halogen, nitro, cyano, C1-C4-alkoxycarbonyl, carbamoyl, C1-C4-alkylcarbamoyl, di(C1-C4)-alkylcarbamoyl, phenylcarbamoyl, sulfamoyl, phenylsulfannoyl, C1-C4-alkylsulfamoyl, di(C1-C4)-alkylsulfamoyl, C1-C4-acylamino, C1-C4-alkyl and C1-C4-alkoxy.