NWUs replaced the utilities. Sailors were complaining about the pockets and liberty restrictions, and that they were just bad for working in. The main reason I read about the NWU color scheme was that it was selected for its ability to hide accidental paint spills. The camo pattern I'm guessing was to give it a more military appearance. It was also not suppose to replace the coveralls for underway usage. The irony was how restrictive it was as far as liberty when it came out. Only recently did they authorize fairly unrestricted wear around town (still no consuming alcohol though). Underway, I've seen a mix of coveralls, khakis, and NWUs. I think it depends on the CO's policy for underway wear. I'm not certain, cause I don't wear them underway so I've never read that instruction.
I personally don't care for them. They're fairly comfortable, but the complete lack of fire resistance is pathetic. I also don't like the enlisted khakis.
But on a side note, they aren't completely worthless in a game of hide and seek:

I'm so glad I'm out. Enlisted khakis? WTF are we going back to, the days of Zumwalt? Screw that.
Personally, I loved being in Hawaii and Guam, and being what was lovingly referred to as a "white-striped snipe" (ET Nuke.) Never wore blues (except on Westpac, then only in winter) and only rarely wore whites (change of command, school.)
Working jacket? Get one from the COB, hide it in your BEQ room, "forget" to turn it back in when you leave (I've got two REALLY good ones.) Peacoat? Hawaii? ROFLMAO!
I'd wear dress blues or whites maybe once a year, CNT's maybe 2-3 times a year. The rest of the time, it was dungarees inport, poopy suit underway.
So nice to get that $400 uniform allowance check once a year, buy a couple pair of dungarees/patches/stencil pens, and spend the rest on beer.