Chips in the sunshine: color constancy with real versus simulated Munsell chips under illuminants adjacent to the daylight locus.

Accurate color judgments rely on a powerful cognitive component. Here we compare the performance of color constancy under real and simulated conditions. Shifts in the u' v' color plane induced by illuminant A (2750 K) and illuminant S (>20,000  K) were measured using asymmetric color matching. A general linear model was used to predict performance from the following dependent variables: chroma ("4" and "6"), illuminant ("A" and "S"), presentation mode ("Real" and "Monitor"), and hue zone ("blue," "green," "yellow," "red," and "purple"). There was a strong overall effect [F(7,264)=78.65, p<0.001]. Post hoc analysis showed that performance was substantially superior under real [chromatic constancy index (cCI)=0.76] compared with simulated cCI=0.55) conditions.