With the three-dimensional (3D) optical analysis as a tool, the optimization of the fringing field effect in the color filter liquid-crystal-on-silicon (CF-LCoS) microdisplays is obtained by changing pixel arrangement, rubbing direction, and liquid crystal (LC) mode. The color purity of the CF-LCoS microdisplays could attain 63% national television system committee (NTSC) level for a typical pixel size of 15 μm. With the optimization, the color fringing effect of CF-LCoS is minimized and the color purity of the device is increased.