coloring material vs colouring material

coloring material and colouring material both are nouns.

Word	Noun	Adjective	Verb	Adverb
coloring material	Yes	No	No	No
colouring material	Yes	No	No	No

As nouns, coloring material and colouring material are synonyms defined as:

coloring material and colouring material: any material used for its color

Other synonyms of coloring material include color, colour.

coloring material (noun)	colouring material (noun)
any material used for its color	any material used for its color