Pigment dispersant, pigment dispersion, and pigment dispersion for color filter

A pigment dispersant represented by the following formula (1):

• ##STR25## wherein X represents a hydrogen atom or an acylamino group;
• Y represents an anthraquinonylamino group having at its 5-position a hydrogen atom or an acylamino group, a phenylamino group or a phenoxy group;
• Z represents an anthraquinonylamino group having at its 5-position a hydrogen atom or an acylamino group, a phenylamino group, a phenoxy group or a C.sub.2-30 aliphatic, alicyclic or heteroalicyclic amine reaction residual group having at least one amino group;
• G represents a reaction residual group of at least one compound selected from C.sub.2-30 aliphatic, alicyclic and heteroalicyclic hydrocarbons each of which has at least one amino group;
• n is an integer of from 0 to 3;
• and when N stands for O, Z represents a reaction residual group of a C.sub.2-30 aliphatic, alicyclic or heteroalicyclic polyamine having at least two amino groups.