In navigation, what is the term for the navigational aids that use colors to signify direction?

The term for navigational aids that use colors to signify direction is buoys. Buoys are floating markers that are typically anchored in place and are designed to provide guidance to mariners. They often utilize different colors and patterns to convey important information regarding safe navigation, such as indicating safe passage, warning of hazards, or marking specific channels. The color of a buoy can indicate which side of a channel is safe to navigate, as in the case of the IALA (International Association of Marine Aids to Navigation and Lighthouse Authorities) system, where red buoys are generally kept on the left when entering from open water, and green buoys are kept on the right.

Markers, while they can refer to various types of navigation aids, do not specifically emphasize the use of color in the same way that buoys do. Lighthouses are fixed structures used to signal maritime navigators and provide reference points, but they typically emit light rather than using color coding to direct vessels. Signaling devices encompass a broader category of tools, which may include sound signals, lights, and other mechanisms, but do not specifically refer to the color coding used in buoys.