A resin composition which can enhance the heat resistance and the humidity resistance of a dye possessing the maximum absorption at wavelengths in the range of 380 780 nm is provided. It is obtained by polymerizing a monomer mixture containing 5 100 wt. % of a monomer represented by the formula: CH.sub.2.dbd.CR--COOX (wherein R denotes a hydrogen atom or a methyl group and X denotes a hydrocarbon group of 4 25 carbon atoms) and/or a fluorine atom-containing unsaturated monomer and containing a dye possessing the maximum absorption at wavelengths in the range of 380 780 nm in an acryl type resin having an acid value in the range of 0 30 mgKOH/g and a hydroxyl value in the range of 0 30 mgKOH/g.