"On ships of the US Navy, First Call is sounded at 0755, 5 minutes ahead of Morning Colors (raising the national ensign), and 5 minutes before Evening Colors (lowering the national ensign). In the absence of a bugle, the word is passed, "First call, first call to colors." The same ceremony takes place on shore establishments but not on ships underway".
This is the way I remember it from my time in the NAVY, back in the Sixties. If you were driving on a Naval Base at 0759 (AM) you should be prepared to "Pull Over" and STOP for Colors at 0800. In the evening, Colors was held AT Sunset.

NB
In
Real Life long after the NAVY. I raize the ensign every day (Never in Bad Weather) the first chance I get in the morning, and Colors at Sunset....Again....IF I
Remember it....I'm just an Old Coot.