I don't wear a flight suit.....but I reckon a dark coloured one would be blimmin useful.
For starters, during the preflight, one is often crawling around under the plane getting dirty. Secondly having numerous pockets seems like a good idea in the cockpit, if for no other reason than to stop your camera getting lost.
The problem comes when you get out of your C150 for lunch - looking like you've just stepped out of an F/A18 at Miramar...
