An environment-compliant image display system, projector, and program that enables the reproduction of appropriate colors even when affected by ambient light. The projector has a color control processing update section that corrects colors by adjusting a LUT in a 3D-LUT storage section and brightness by adjusting a grayscale characteristic in a ID-LUT storage section, in order to increase the output in at least a lower grayscale range if the environment is affected by ambient light, based on environmental information that has been measured by a color light sensor.