By setting the color temperatures of displays included in a display system to a desired value, the life of the displays and display system is extended. A method for this includes acquiring outputable maximum luminances of the displays at each of multiple color temperatures, comparing the outputable maximum luminances of the displays at the same color temperature and determining the lowest maximum luminance value for each of the color temperatures, a color temperature corresponding to the highest of the lowest maximum luminance values identified for each of the color temperatures, and setting color temperatures of at least two of the displays to the common set color temperature.