What is the name of the ceremony for raising and lowering the national ensign while underway?

The correct term for the ceremony that takes place for raising and lowering the national ensign while a ship is underway is "Colors." This ceremony is a significant display of respect and serves as a way to honor the national flag. It usually occurs at specific times during the day, commonly at sunrise and sunset, which align with the rituals of displaying the ensign on naval vessels.

The term "Morning colors" refers specifically to the act of raising the flag in the morning, while "Evening colors" pertains to lowering the flag in the evening. These terms can often be used to describe the specific moments of the ceremony but do not encompass the overall practice while a vessel is underway, which is broadly titled "Colors." Therefore, identifying the ceremony simply as "No ceremony" misses the importance and formal practice involved in these actions regarding the national ensign.