Color Quality Scale (CQS) is a quantitative measure of the ability of a light source to reproduce colors of illuminated objects. Developed by researchers at NIST,[1] the measure is a possible answer to the criticism of the widely used color rendering index.[2]
Pousset et al. developed a psychophysical experiment in order to evaluate light quality of LED light sources.[3] It is based on colored samples used in the Color Quality Scale. Predictions of the CQS and results from visual measurements were compared.