heather mixture vs colouring

heather mixture and colouring both are nouns.

Word	Noun	Adjective	Verb	Adverb
heather mixture	Yes	No	No	No
colouring	Yes	No	No	No

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

heather mixture: interwoven yarns of mixed colors producing muted greyish shades with flecks of color
colouring: a visual attribute of things that results from the light they emit or transmit or reflect

Other hypernyms of heather mixture include color, coloring, colour.

heather mixture (noun)	colouring (noun)
interwoven yarns of mixed colors producing muted greyish shades with flecks of color	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