Which color is NOT a part of the color-coded markers used in the Phone and Distance Line?

The Phone and Distance Line markers utilize a specific set of colors that are standardized for navigation and communication purposes. Among these, green, red, and blue are established as part of the color-coding system, each serving a unique functional purpose in the signaling process. Green typically indicates safe passage or a go signal, while red is often used to denote hazards or prohibitions. Blue can represent various informational signals depending on the context.

Orange, however, is not included in this recognized set of colors. It is essential to understand the significance of each color in navigation to ensure accurate interpretation and proper adherence to maritime safety signals. Therefore, recognizing that orange does not fit within the established color scheme helps clarify the key elements of the Phone and Distance Line system in maritime contexts.