Psychophysical experiments were carried out for describing color appearance under 12 different sets of viewing conditions including variations of neutral backgrounds, sample sizes, textures, sample types and color attributes. The results on saturation based upon 132 colored cube samples are discussed here. It was found that observers can be trained to scale saturation with a great accuracy. There is little difference in the results for the white, gray and black backgrounds studied. Saturation is dependent upon lightness and colorfulness, i.e. an increase in saturation will increase colorfulness but with a reduction of lightness. It was also found that the saturation scale of CIECAM97s did not fit well to the visual results. An improved scale was developed.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.