colour vs gray

colour and gray both are nouns.

Word	Noun	Adjective	Verb	Adverb
colour	Yes	Yes	Yes	No
gray	Yes	Yes	Yes	No

As verbs, gray is a hyponym of colour; that is, gray is a word with a more specific, narrower meaning than colour:

As verbs, gray is a hyponym of colour; that is, gray is a word with a more specific, narrower meaning than colour:

colour (noun)	gray (noun)
a visual attribute of things that results from the light they emit or transmit or reflect	horse of a light gray or whitish color
the appearance of objects (or light sources) described in terms of a person's perception of their hue and lightness (or brightness) and saturation	clothing that is a grey color
the timbre of a musical sound	a neutral achromatic color midway between white and black
interest and variety and intensity	any organization or party whose uniforms or badges are grey
an outward or token appearance or form that is deliberately misleading	the SI unit of energy absorbed from ionizing radiation; equal to the absorption of one joule of radiation energy by one kilogram of matter; one gray equals 100 rad
(physics) the characteristic of quarks that determines their role in the strong interaction
any material used for its color

colour (adjective)	gray (adjective)
having or capable of producing colors	of an achromatic color of any lightness intermediate between the extremes of white and black
	intermediate in character or position
	showing characteristics of age, especially having grey or white hair
	used to signify the Confederate forces in the American Civil War (who wore grey uniforms)

colour (verb)	gray (verb)
change color, often in an undesired manner	turn grey
add color to	make grey
affect as in thought or feeling
give a deceptive explanation or excuse for
decorate with colors
modify or bias