The present invention provides a mixed crystal having absorption properties that are excellent for color reproducibility as a blue pigment, and including a compound represented by the following Formula (I) and a compound represented by the following Formula (II), and a colored pigment dispersion composition including the mixed crystal and a medium. In Formula (I), X represents —SO—Z, —SO2—Z, —SO2NR1R2, —SO3R1, —CONR1R2 or —CO2R1; Z, R1 and R2 each independently represent an alkyl group, an aryl group, a heterocyclic group or the like; Y represents a monovalent substituent; M1 represents a hydrogen atom, a metal element or the like; and a and b are integers from 0 to 16 and satisfy the relationship of 0≦a+b≦16. In Formula (II), G1 to G4 and Q1 to Q4 each independently represent a carbon atom or a nitrogen atom, and A1 to A4 each independently represent a group of atoms necessary for forming an aromatic ring or heterocycle with the respective G1 to G4 and Q1 to Q4. Here, at least one ring among the four rings to be formed is a heterocycle. Each aromatic ring or heterocycle may have a substituent; M2 represents a hydrogen atom, a metal element or the like.