What is the color of the side light on a starboard side of a vessel?

The side light on the starboard side of a vessel is green. According to the International Regulations for Preventing Collisions at Sea (COLREGs), vessels are required to display specific lights to indicate their position and orientation to other vessels. The green light represents the starboard side, while the red light represents the port side. This color distinction is critical for navigational safety, as it allows mariners to identify a vessel’s direction and operational status during the nighttime or in poor visibility conditions. Thus, the green light on the starboard side enables other vessels to determine whether they are encountering the vessel head-on, overtaking it, or crossing its path, which is essential for safe navigation.