We have a warning light that comes on as an indication of an unsafe condition. This is obviously backwards since a light bulb failure could falsely indicate a safe condition. I would like to replace this light with a set of lights, one indicating a safe condition and the other indicating an unsafe condition. In order to help make my case I would like to have any supporting documentation from an agency such as IEEE or NFPA which would address standards for such situations. So-far, my internet search hasn't yielded any results... does a standard exist for the fail-safe implementation of such equipment?