olive drab vs olive drab

olive drab and olive drab both are nouns.

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

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