The relation between perceptual image quality and naturalness was investigated by varying the colorfulness of natural images at various lightness levels. A systematic difference was found between quality and naturalness judgments. This difference, reflecting the subjects' preference for more colorful but, at the same time, somewhat unnatural images, was most noticable at the original lightness level and diminished with decreasing lightness, in particular at the lowest lightness level investigated.
Huib de Ridder, "Naturalness and Image Quality: Influence of Chroma Variation at Various Lightness Levels" in Proc. IS&T 3rd Color and Imaging Conf., 1995, pp 140 - 142, https://doi.org/10.2352/CIC.1995.3.1.art00037