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...
That's true, but you don't want to make it worse. I always thought blue and the darker navy blue were specified for those colors because blue dyes are the cheapest and most permanent dye color available, or were back when that color was first used.