armed forces vs olive drab

armed forces and olive drab both are nouns.

Word	Noun	Adjective	Verb	Adverb
armed forces	Yes	No	No	No
olive drab	Yes	No	No	No

armed forces (noun)	olive drab (noun)
the military forces of a nation	a cloth of an olive-brown color used for military uniforms
	military uniform of the United States Army; made from cloth of a dull olive color
	a dull greyish to yellowish or light olive brown