Process for producing special color effects in shaped articles

A process for producing an article having a surface color swirl effect comprising: a) providing at least one color concentrate comprising a colorant carried in a mixture of a crystalline organic polymer and an amorphous organic polymer; b) providing a flowable organic polymer compatible with the color concentrate of step a); c) transferring the color concentrate of step a) and the flowable organic polymer of step b) to an extruder or molding machine; d) providing sufficient heat to maintain the temperature of the mixture of step c) above the glass transition temperatures of the polymers of steps a) and b) and above the temperatures at which the amorphous polymers of step a) melt or flow, but below the melting or flow temperature of the crystalline polymer of step a); e) forming an article with sufficient pressure and mixing necessary to impart a color swirl effect on the article surface.