Disclosed are thermally-stable, red, anthraquinone colorants which contain one or more ethylenically-unsaturated, photopolymerizable radicals and which may be copolymerized with ethylenically-unsaturated monomers to produce colored compositions such as colored acrylic polymers, colored polystyrenes, and similar colored polymeric materials derived from other ethylenically-unsaturated monomers. The compounds possess good stability to ultraviolet light, good solubility in vinyl monomers, good color strength and thermal stability. Also disclosed are acrylic polymeric materials, i.e., polymers derived from acrylic acid esters, methacrylic acid esters and/or other copolymerizable vinyl compounds, having copolymerized therein one or more of the colorant compounds of the present invention.