We used to wear camouflage helmet covers... It was a big deal, because Flight E generally didn't get around to making yours until you were LLL complete. It was awesome when you started to fly with it, because you had "arrived."
That's got to be an East Coast thing. Helmet covers weren't viewed as a rite of passage on the Left Coast - just something Flight E got around to doing when they had the time. All pilots/aircrew were directed to have one, so I got one.
Never wore the damn thing. I was in a MEU squadron, and I figured I ran a bigger risk of going swimming than I did of Charlie spotting my reflective helmet in the cockpit of a 12-ton helicopter...with at least one other 12-ton chopper nearby. (If I'm that close, the gig is up anyway!)
Our skid guys always wore their helmet covers, and all I could think of is the extra work it would take for our HSC bubbas to find them if the unexpected happened. (Similar to the head scratching I do when I see Sailors wearing Aquaflage or dark blue coveralls while underway. Who are they hiding from? All it does is make the search for overboard Sailors more difficult.)
In any event, I'll make my annual plug for the return of fluorescent orange flight suits. Hell, if someone could invent a fluorescent orange flight suit with water-activated strobes, embedded ELTs, and self-firing flares, I'd wear it.