We present numerical simulations for an acrylonitrilebutadiene-styrene copolymer (ABS) resin extrusion in an industrial conventional single-screw extruder. Based upon the flow field patterns obtained in the simulations, a particle tracking procedure was employed to obtain information about the spatial distribution of particle tracers of two colors. Results of the simulation were compared with experimental data obtained under similar extrusion conditions. To evaluate the degree of color mixing and color homogeneity for the system, we employ a specific index calculated based upon the Shannon entropy for two species populations. POLYM. ENG. SCI.,