Fluorescent colorant compositions, coloring process and colored articles

A fluorescent colorant composition comprising a pigment and a resin, wherein said pigment is a crystalline, azo-based, fluorescent pigment obtained from a coupling reaction of a diazo compound, which was obtained from an amine represented by the following formula (1) or (2), with a coupler represented by the following formula (3) or (4):

• wherein X and Y may be the same or different and each independently represents a methyl, methoxy or ethoxy group, and Z represents an —NHCO-A or —NH-A group in which A represents a substituted or unsubstituted aromatic ring,
• wherein L represents a halogen atom or an RCOO— or —COOR group in which R represents a hydrogen atom or a C1-C10 alkyl group, n stands for an integer of from 0 to 4, M represents a —CONH2 group, —CONH-A group in which A represents a substituted or unsubstituted aromatic ring, or —CO—NH—CO group which is an imido group forming an imide ring, and m stands for 0 or 1.