I don't get why the branches in which very few folks are likely to need camo (basically anyone other than the army, then, and some sub-divisions of other branches like the marine corp) don't go with old-school olive drab or navy or something. Those single-color uniforms with a slightly dressy cut looked damn slick. I'd think that'd be better for recruiting or improving morale or whatever than the camo uniforms (which, often as not, are the butts of jokes and not considered at all appealing)
Then again, maybe those old styles only looked good when they were made with nice materials, like wool and heavy waxed canvas, and would look bad with cheap modern synthetics.
One advantage of camo uniforms for working utility uniforms is they tend to be effective in hiding things like grime and mud, which consequently means you need to launder them less frequently to keep up the same appearance. If you've got a solid single-color uniform, chances are that these will stick out like a sore thumb. That was one thing that sailors liked about the old US Navy NWU (the one that camouflaged you very effectively if you fell in the water)--really good at hiding paint drips.
With regards to looking good, I don't think it's necessarily that the look good with appropriate materials, but more that they look good only when they are properly starched and the like to maintain crisp lines.
Then again, maybe those old styles only looked good when they were made with nice materials, like wool and heavy waxed canvas, and would look bad with cheap modern synthetics.