Final answer:
A north cardinal buoy is marked with black and yellow colors, with black being on top. These buoys are used in maritime navigation to convey the location of safe water and are identified at night by their unique light sequence.
Step-by-step explanation:
The colors of a north cardinal buoy are black and yellow. North cardinal buoys are used in maritime navigation to indicate where the safest water is relative to the buoy position. Specifically, a north cardinal buoy will have its colors arranged with black at the top and yellow at the bottom. In the dark, these buoys are identified by their distinctive flashing lights: a white light that emits a quick or very quick flashing sequence of six times followed by one long flash every fifteen seconds. If equipped with a top mark, it will be two black cones pointing upwards.
Mariners use these buoys to navigate safely in waters around the world, avoiding hazardous areas. Understanding the colors and patterns of maritime navigational aids like cardinal buoys is critical for the safety of vessels at sea.