What does "dichotomous buoy" mean in terms of visual identification?

A "dichotomous buoy" is specifically characterized by its use of two distinct colors to convey important navigational information, particularly to differentiate between safety and danger. In the context of the IALA Maritime Buoyage System, this term is used to help mariners visually identify the status and significance of a buoy. For instance, one color may indicate a safe passage, while another warns of hazards or dangerous areas. The clear use of two colors provides an immediate and easily distinguishable guide for navigators, enabling them to make quick judgments about their navigation near these buoys.

In contrast, the other options describe features that do not align with the definition of a dichotomous buoy. Some buoys might change color in response to weather conditions, rotate to indicate direction, or emit sound signals, but these characteristics do not pertain directly to the fundamental concept of a dichotomous buoy as defined in the buoyage system.