After looking at the photos I took last night I've come to the conclusion that the colour of training shirts was based on what they were doing this weekend and their status of fitness, the players appeared to have been thrown into 4 groups.
Blue shirts = Cabra
Yellow = Ballina
Pink = limited training, no contact
other= injured
Wade McKinnon = Yellow
Luke Burt = Yellow
Ben Smith = Yellow
Timana = Blue
Junior = Pink
Morris = Other
Timmy = Yellow
Wags = Yellow
Moro = Blue
Hindy = Pink
String = Pink
Pig = Pink [Kind of ironic really]
Caylo = Blue
Reddy = Blue
Williams = pink
Chalk = Yellow
Frog = Yellow
Peto = yellow
Jeremy Smith = Blue
Marcus P = Other [although did run around in a non contact capacity with the boys]
Widdo = Yellow
Chad = Yellow
Henry P = Blue
Mick Vella = Pink
PJ = Blue
Fui = Blue [can't wait to see him in friday night]
Jarryd Hayne = Yellow
Ash Graham = Blue [ looked sharp out there, too]
Kris inu = Blue
Feleti = Blue
Blake Green = Blue
Drew Dalton = yellow
Jack Afa = yellow
Josh Cordoba = Yellow
Adam peek = Yellow
Jim storer = Other
Aaron cannings = Yellow
Kris keating = Yellow
Weller Hauraki = Yellow
Zeb Taia = Yellow
Peter Lewis = Yellow
Brendon Oake = blue
Matt Keating = Yellow
Justin Tsolous = Pink
I think that's it!!