A series of visual experiments were designed to determine whether naive observers typically evaluate chroma or colorfulness when judging color appearance. A total of 7 observers were asked to determine a color appearance match between Munsell samples under the same illuminant (C) at different levels of illuminance. Color appearance matches were determined for 12 Munsell samples, under five reference and matching scene illuminance conditions, for four experimental techniques. The four experimental techniques were haploscopic, simultaneous inspection, successive inspection, and short-term memory matching. Results suggested that a chroma match was most important when observers were evaluating the color appearance of two scenes at different levels of illuminance. Results were also compared to predictions of two color appearance models. While similar trends were apparent between the experimental results and the two model\u27s predictions, only the Hunt model\u27s chroma term satisfactorily predicted experimental observations
