Sailors still fall overboard. You don't want camouflage at sea, especially camouflage that will blend in with a choppy sea with white caps.
Since when does the Navy give a hoot about visibility? Those blue dungarees don't exactly show up real well at night when you're floating in the middle of the South Pacific watching your ship disappear over the horizon. If man-overboard visibility was the main criteria, the Navy would make all the uniforms International Orange.
Besides, real squids stay safely below decks when the ship is underway...