To provide an ink composition which is for use in inkjet printing, has a good hue and is excellent in light resistance, ozone resistance and moisture resistance.

The aqueous solution of a dye contains ≥7.0 mass% of a dis-azo compound expressed by formula (1) or its salt. In the formula, either of X and Y is a hydrogen atom and the other is a sulfonic group; either of A and B is a hydrogen atom and the other is a sulfonic acid group; R1, R2, R3 and R4 are each a hydrogen atom, a methyl group, ethyl group, methoxy group, ethoxy group, acetylamino group or ureido group; R5 and R6 are each a hydrogen atom, a methyl group, ethyl group, methoxy group, ethoxy group, acetylamino group, a chlorine atom, a hydroxy group or carboxy group.