FED, Steady Red , Green and White (or combinations of those colors) for nautical navigation lights....thus the rotating beacon.....or strobes.
No expert but Submarines use a flashing Amber Light when surfaced as I recall.
32 CFR § 707.7 - Submarine identification light.
§ 707.7 Submarine identification light.Submarines may display, as a distinctive means of identification, an intermittent flashing amber beacon with a sequence of operation of one flash per second for three (3) seconds followed by a three (3) second off-period. The light will be located where it can best be seen, as near as practicable, all around the horizon. It shall not be located less than two (2) feet above or below the masthead lights.