The United States Armed Forces requires the same courtesies to "To the Colors" as to the national anthem.
[1] Note that the call To the Colors is named and employed differently between US Military Branches.
In the US Army, To the Colors is sounded at the moment the flag begins to be lowered in the evening, and is immediately preceded by "Retreat" which marks the end of the working day.
See Manual for Buglers, U.S. Navy,[2] articles 35 and 75 pertaining to Morning and Evening Colors calls.
In the Boy Scouts of America,[3] To The Colors is recommended for both raising and lowering the flag (preceded by Retreat in the evening as per the US Army protocol).