The ANOVA results showed that lighting color did significantly affect visual performance (mean percentage and mean answer). White light resulted in better visual performance than yellow light. Three reasons may be offered. First, because the lighting color slightly shifted the color coordinates (x, y) of text colors. Second, the subjects were more accustomed to the white light than yellow light condition because white light is the more common lighting color for general offices. Third, Chung and Pease [14] showed that the pupil size is larger under yellow light than with luminance-matched white light. Enlarged pupils over a long period might increase eye fatigue and then reduce visual performance.