When encountering vessels in darkness what do visible white green and red lights mean?

In darkness, vessels display specific colored lights to indicate their type and direction of travel. A white light typically indicates a vessel is anchored or underway, a green light is shown on the starboard (right) side, and a red light is shown on the port (left) side. When navigating, a vessel displaying a green light is moving towards you from its starboard side, while a red light indicates it is coming from the port side. Understanding these lights helps in determining the relative position and course of other vessels at night.