When I was growing up on Navy bases, there was no question at all that if we were outside, we stopped everything we did, faced the colors, and stayed respectfully still until the ceremony was over, and those ten notes would play: “Dah Dah Dah Da Da Da Dah Dah Dah Dah!”
And nobody ever deviated from that behavior, either. Nobody watched us, but we knew we had to do, and we should do it. It was inculcated with us.
If I ever goofed around during colors, and my mother or father found out, they would have been very displeased and severe. It was all about respect. So we did it.
That said, it didn’t stop us (if we looked over and saw the Marines or Sailors marching out to the flagpole) to run at high speed to get under cover, but even if we were 10 feet away from the cover or door when it started, we would stop dead in our tracks and turn around.