I am pretty sure its just colours. My advise is get the best value frame and put the money in to the wheels, aerobars etc - these date far slower than frame colours which chage every year and are alawys going of date in less tha 12 months!
A difference with an 08 & 09 maybe the fork - best to get the 3T rather than the earlier model.
RobC
P3 2009
Bianchi 2000 TT
Quintana Roo Kilo 1999 650
Softride Rocket TT 2005 650