We investigated the effects of ambient illumination on the color appearance of CRT which was positioned in a room illuminated by experimental illuminants, F2, F5, and F8. The luminance of these illuminants were controlled at three levels. The observers adjusted a color patch on the CRT to find achromatic matching on a random color background. The chromaticity of the achromatic color was shifted toward that of the illuminant, which implies the change of the observer's chromatic adaptation state. The shift ratios, calculated in the uniform space u'-v', increased according to the increase of the distance between chromaticities of CRT white and those of illuminants and increased according to the increase of luminance level of the illuminants. These results were implemented in a monitor profile for a color management system to get more consistent color appearance of the CRT which was viewed under various ambient illuminations.