Sounds like you found a typo (since Wikipedia[0] lists "luminance" vs "lightness") Why don't you message the creator (Nate Baldwin[1][2]), and bring it up? ..

Sounds like you found a typo (since Wikipedia[0] lists "luminance" vs "lightness") Why don't you message the creator (Nate Baldwin[1][2]), and bring it up? ...though since the creator referenced not only the Wikipedia article, but several others on that site, perhaps it's not a typo? --------- [0] https://en.wikipedia.org/wiki/Helmholtz%E2%80%93Kohlrausch_effect https://en.wikipedia.org/wiki/Helmholtz%E2%80%93Kohlrausch_e... [1] https://colorandcontrast.com/#/references https://colorandcontrast.com/#/references [2] https://natebaldw.in https://natebaldw.in