PURPOSE: To obtain a high-quality color image using a colorant superior in shelf stability in a solvent by incorporating a dye shown by a specific general formula as a colorant in each of magenta ink, yellow ink, and cyan ink.

CONSTITUTION: As a colorant, magenta ink incorporates one or more kinds of dyes shown by a formula I (Q1-Q4 individually respresent benzene ring or naphthalene ring; X represents -O- bond or the like; and (n) is 0 or 1). As a colorant, yellow ink incorporates one or more kinds of dyes shown by a formula II (Q is -NHCONH- bond or the like; X1, X2 are hydrogen atom or the like; R is methyl group or the like; and (n) is 0 or 1). As a colorant, cyan ink incorporates one or more kinds of dyes shown by a formula III (M is an alkali metal or the like; (m) is 1-4; and (n) is 0-3). As a colorant, black ink incorporates one or more kinds of dyes selected out of acid, neutral, and basic carbon blacks. This is used for forming a color image.