Lightness (L*)
Definition
A perceptual attribute expressed in the CIELAB color space as L*, a dimension scaled commonly from 0 (black) to 100 (reference white) that represents perceived lightness of diffuse, opaque samples by applying a nonlinear transformation to relative CIE Y (luminance) with respect to a specified reference white; L* is dependent on the chosen reference and therefore on viewing/illuminant conditions.