Herein, the vertical aligned nematic color filter liquid crystal on silicon (VA CF-LCoS) microdisplay was studied, and the fringing field effect in micro-pixels was optimized by changing the pre-tilt angle and pixel size. To further optimize device performance, a three-dimensional (3D) optical model of the VA CF-LCoS was established using circularly polarized light as the incident light source. Results reveal that the optical reflection efficiency of VA CF-LCoS can be considerably improved when a circularly polarized light is used as the illumination source. Herein, using 3D optical analysis, a completely different conclusion has been reported compared to those reported by former researchers who use two-dimensional optical analysis: the black lines in bright sub-pixels caused by the fringing field effect can only be reduced via optimization, and not completely eliminated.