Depending on your trade, you may not wish (may not be allowed) off Base. Sometimes NCDs and sea boots tend to get a little rough looking and therefore are not permitted off Base. I cringe when I see a sailor in the grocery store on the way home in ratty looking NCDs. Without making a scene, I (as will most) will make a comment to said individual. Having said that, every now and then, you will see a CPO or Lt(N) looking like he just climbed out of the AAMR bilge!!
Bottom line here, if your NCDs look pretty much like they did the day they were issued, wear them proudly to and from work (and save yourself the hassle of changing). For me, I used to have my 'work' boots and my 'going home' boots too.
NOTE: As a hard sea trade, the only time you will ever wear green cadpat is if you are part of the MARLANT/MARPAC Nijmegen Team.