Blue for gun ammo is incendiary, while blue on other ordinance is inert. All blue ordinance can be flown and dropped, while blue stripe only, is not approved for flight, but only for ground training use.
Long years ago I was shipped an AIM 9 for test program. Live seeker head, but inert and ballasted missile body. Unfortunately the goobers that crated it, did so in a way that the inert bands were completely covered. Lots of consternation trying to figure out if we had a live missile sitting in our office or not!