chromatic color vs colouring

chromatic color and colouring both are nouns.

Word	Noun	Adjective	Verb	Adverb
chromatic color	Yes	No	No	No
colouring	Yes	No	No	No

As nouns, colouring is a hypernym of chromatic color; that is, colouring is a word with a broader meaning than chromatic color:

chromatic color: a color that has hue
colouring: a visual attribute of things that results from the light they emit or transmit or reflect

Other hypernyms of chromatic color include color, coloring, colour.

chromatic color (noun)	colouring (noun)
a color that has hue	the act or process of changing the color of something
	a visual attribute of things that results from the light they emit or transmit or reflect
	a digestible substance used to give color to food