Scratch that, there was a rule change in 2013... (Doing some good ol' reseach...)
Same rule now reads as:
"When a player enters the game after changing his jersey number, he must report to the referee, who then informs the opposing head coach and announces the change. Such a player who enters the game without reporting commits a foul for unsportsmanlike conduct"
So there you go, as long as the player notifies referee, the referee announces it. A jersey change during game can occur during the game.
http://www.ncaa.org/sites/default/files/Final%202013%20and%202014%20Football%20Rule%20Changes.pdf
That sounds right. Was it UCLA a couple years ago that we had to have an announcement every time their holder or someone came into the game because he was a different number?