There is provided a method for producing colorants which can exhibit excellent color development even in a small amount and are low in thixotropy.The constituent feature of the present invention comprises: enhancing the molecular extinction coefficient of the coloring matter substance by ion exchanging method, to afford a room for increasing B (resin) of P/B; then a composition is designed and employed to enhance the effect increasing the polar group concentration which is a role of resin and the quality of the effect; it thus becomes possible to achieve the limit value of the molecular extinction coefficient as much as possible and to eliminate the factors adversely affecting the present process.