Adapting chromaticities are not considered in characterizing the degree of chromatic adaptation in various chromatic adaptation transforms (CATs). Though several recent studies have clearly suggested that the effect of adapting chromaticities on degree of chromatic adaptation should not be ignored, these studies were only carried out under a single adapting luminance level. This study was carefully designed to systematically vary the adapting luminance and chromaticities to investigate whether the adapting luminance and chromaticities jointly affect the degree of chromatic adaptation. Human observers adjusted the color of a stimulus produced by a self-luminous display to make it appear the whitest under each of the 17 different adapting conditions. It was found the adapting chromaticities and luminance jointly affected the degree of chromatic adaptation. At a same adapting luminance level, the degree of chromatic adaptation was found lower under a lower adapting CCT (i.e., 2700 and 3500 K). A higher adapting luminance can significantly increase the degree of chromatic adaptation, especially when the adapting CCT was low (i.e., 2700 and 3500 K).