L*

Represents a standard or sample’s position on the lightness axis in either CIELAB or CIELCH color space.

a*

Represents a standard or sample’s position on the green/red axis in CIELAB color space, green being in the negative direction and red being in the positive direction.

b*

Represents a standard or sample’s position on the blue/yellow axis in CIELAB color space, blue being in the negative direction and yellow being in the positive direction.

C*

Represents a standard or sample’s chroma value in CIELCH color space.

H*

Represents a standard or sample’s hue value in CIELCH color space.