Brightness L - the extent to which an area appears to
exhibit light.
Colorfulness M - the extent to which the hue is apparent.
Saturation Suv - relative colorfulness judged in proportions
to the brightness of the object itself.
Chroma C*uv - the colorfulness of an area judged in proportion
to the brightness of a similarly illuminated area that appears
to be white (or highly transmitting).
Lightness J - the brightness of an area judged relative
to the brightness of a similarly illuminated area that appears
to be white (or highly transmitting, in the case of transparent
objects).