Rule 1
Section 4
Article 2
Part D
States: "
Numbers shall not be changed during the game to deceive opponents"
According to the rule book, cannot switch jerseys during the game. Live ball penalty. 15 yards from previous spot. Player is DQ'd.
http://rules.bafra.org/rules/rulebook/2013/1.html
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