…Further, the only time an anchor light or a steaming light should "look like a star" to a helmsman, is during a zero bearing rate (head-on) collision situation, where the light presents the illusion of not moving. In any other crossing scenario, the light will be moving across the helmsman's field of view rapidly enough to differentiate it from a star.
Look, this argument is as old as the hills. People have complained for years about how anchor and steaming lights look like streetlights and automobile lights when compared against the shoreline. There's always going to be an excuse as to why a skipper didn't see someone or suffered a collision.
LED comes in a variety of colors: yellow, incandescent white, pale white, cool white, super lime yellow that are white or off white.
LED Color Chart
An off white LED would be better if it can help differentiate from the background white colors because the zero bearing (head-on) situations at night are really dangerous. The running light will not move against the background and the mind will be looking for something that is moving. I would think anything that would differentiate a running light from the background with a bit of color shift from the normal LED white used on running lights would help.
Unfortunately a rotating beacon or strobe not would be a good idea as it is against Rule 36, Signals to Attract Attention states: If necessary to attract the attention of another vessel, any vessel may make light or sound signals that cannot be mistaken for any signal authorized elsewhere in these Rules, or may direct the beam of her searchlight in the direction of the danger, in such a say as not to embarrass any vessel. Any light to attract the attention of another vessel shall be such that it cannot be mistaken for any aid to navigation. For the purpose of this rule, the use of high intensity intermittent or revolving lights, such as strobe light shall be avoided. The prohibition of strobes does not apply to Inland Rule. For inland rules a white flashing light from 50 to 70 times per minute is a distress signal.