olive drab

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A grayish olive to dark olive brown or olive gray.
• noun Cloth of this color, often used in military uniforms.
• noun A uniform made from cloth of this color.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A greyish green colour, like that of a ripe green olive.
• noun Cloth of an olive drab colour, used often for military uniforms.
• adjective Of a greyish green colour, like that of a ripe green olive.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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