This study reports on the results of the subjective evaluation of a color gamut required for a preferred color reproduction using a pseudo ultra-wide gamut display. The results indicate three things: (1) pseudo ultra-wide gamut displays are equivalent to conventional displays in terms of appearance and are useful for subjective evaluations; (2) the maximum chroma of the required color gamut is near optimal color; (3) the maximum chroma changes depending on image contents.In this evaluation, test images were presented on a display with varying chroma values and subjects were asked to evaluate their preference of the images. The scores were expected to decrease after reaching and exceeding a certain chroma. The thresholds were the limits of the color gamut required for preferred color reproduction.The test images consisted of natural object images and artificial object images. The images were red, yellow, green, purple, and magenta with high luminance.These images were displayed on a pseudo ultra-wide gamut display, based on Adobe RGB display and the adaptation luminance of white point was set to 60% of the maximum luminance. Therefore, the display used in this experiment was able to display some colors out of Adobe RGB gamut in a higher luminance. Additionally, its color gamut was wider than optimal colors in some areas.