Probably the best way to communicate to all concerned that there has been an out of bounds violation is to simply sound the whistle, stop the clock, verbalize the color and then give a direction signal.
I often see officials who sound the whistle, stop the clock and then verbalize “off white, black ball.” This technique often causes more confusion that it does communication. What happens is that sometimes coaches, players and fans hear “white” and then think they have been awarded the ball for a throw in. But, moments later the official is pointing the other direction and awarding the ball to the opposition.
Logic tells us that if the ball is awarded to “white,” black was the last to touch it.
Coaches sometimes think that the official has changed his decision and may think he/she was intimidated into doing so. Sometimes players start in the wrong direction and then have to come back the other way. Mommies and dads think you have just screwed their children’s team because they heard you say “white.”
If an official thinks there needs to be additional communication involving the out of bounds situation it may be best done after verbally giving the color and after giving the direction signal.
So, the official sounds the whistle, verbalizes “white” gives the direction signal for white and then if he/she wants to, give a touch signal, then point at an opposing player and “he got it.”
The same thing holds true if a player with the ball steps on the end line. Many officials sound the whistle, then instead of stopping the clock, they point at the boundary line while starring at the floor and then say “white.” It may communicate better and faster to simply sound the whistle, announce the color and then point at the boundary line if you think additional information is needed.
The most important information is which team gets the ball. Say that color first, then give the direction signal. Anything else comes after.