coloring vs food colour

coloring and food colour both are nouns.

Word	Noun	Adjective	Verb	Adverb
coloring	Yes	No	No	No
food colour	Yes	No	No	No

As nouns, coloring and food colour are synonyms defined as:

coloring and food colour: a digestible substance used to give color to food

Other synonyms of coloring include colouring, food color, food coloring, food colouring.

coloring (noun)	food colour (noun)
the act or process of changing the color of something	a digestible substance used to give color to food
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