Interpretation of the psychophysical results on preferred CCT and Duv when investigating colour preference of lighting

Abstract

In this paper, the authors discuss a hot and disputable topic in colour quality evaluation for lighting. During the past years, it is quite common to investigate the impact of CCT and Duv on colour preference of lighting. Theoretically speaking, the conclusions of those work are not perfectly rigorous. First, there are numerous SPDs corresponding to a same CCT or Duv so counter-examples could always be raised. Second, most studies did not control colour rendition properties (quantified by colour quality metrics) of the experimental lights, thus it was not reasonable to solely ascribe the difference of visual perception to the impact of CCT or Duv. With the aim of comprehensively interpreting the rationality and limitations of those research, in this work we critically reviewed several typical studies and analyzed the correlation between CCT/Duv and 25 colour quality metrics. The result shows that although the experimental settings and protocols of current studies are diverse, in general their conclusions of preferred CCT/Duv are consistent. Such conclusion indicates that for practical use CCT and Duv could be regarded as effective indicators for evaluating colour preference because of the significant correlation between those measures and certain colour quality metrics.