Which color disc indicates that a system is fully out of service?

The color disc that indicates a system is fully out of service is white. In the context of sprinkler systems and fire protection, color coding is utilized to quickly convey important operational statuses to personnel. A white disc signifies that the sprinkler system is not operational, which means that it should not be relied upon for fire suppression.

This distinction is critical for ensuring safety and proper response in emergency situations. Personnel can easily recognize that a white disc means the system is entirely out of service and can take necessary actions, such as implementing alternative fire protection measures or addressing the issues with the sprinkler system. Understanding these color codes is essential for effective fire safety management and operations.