This ("lightness prediction") is one of the design criteria for the OKLAB color space, see: https://bottosson.github.io/posts/oklab/ https://bottosson.github.io

This ("lightness prediction") is one of the design criteria for the OKLAB color space, see: https://bottosson.github.io/posts/oklab/ https://bottosson.github.io/posts/oklab/ The HSV color spectrum in the oklab article shows very clearly how the OKLAB lightness is a much better metric for whether a color is bright or not than HSV-value. This article by comparison is very grayscale-focussed and concise, but gives less information on the physics behind it.