Final answer:
Unacknowledged alarm conditions returning to normal are typically not assigned a specific light color, but green commonly signifies normal operation. Acknowledgement actions are generally needed to reset alarms.
Step-by-step explanation:
An unacknowledged alarm condition that has returned to normal is typically not indicated by a specific light color because it varies depending on the system's design. However, a green light often indicates normal operation conditions in many systems, suggesting that everything is functioning properly. It is less common for a system to specifically indicate with a light color that a condition has returned to normal but remains unacknowledged. Normally, an acknowledgement action is required to clear or reset the status indicator.