a process for molding plastic parts includes the steps of providing two or more colors of pigmented powder particles of thermoplastic material ; casting the particles against a heated surface to form non - patterned layers of particles with voids therebetween ; heating the layers to form color blended fused fringe zones between the particles which fill the voids to form a solid , multi - colored , three - dimensional article while each particle retains its discrete particle core which maintains each particle &# 39 ; s central or original color concentration and which cores have discernible light transmissive properties .