Statistical Approach to Color Quality of Solid-State Lamps*

Color rendition vectors of 1269 spectrophotometrically characterized test samples of the Munsell palette were analyzed for common solid-state and fluorescent lamps with respect to reference illuminants. The vectors were individually normalized to the size of color discrimination shapes obtained from the known data of just perceived differences of chromaticity and luminance. Based on the analysis performed, we categorized the rendered colors into three groups—colors rendered with high fidelity, colors rendered with increased saturation, and those rendered with distorted hue—and introduced three corresponding indexes to assess the color quality of light sources. In combination with the correlated color temperature, these indexes, which represent important color quality characteristics of white light, constitute a simple 4-D metric for an advanced rating of illumination-grade lamps.