Actually, the V2's are gray and the V1's are black. The V2's also have dividers where the V1's don't.
They tend to last longer because the reed tips aren't exposed like they are on the V1's. The V2's are also marginally larger all around. In a limited motor, you can't tell them appart (performance wise).
Here is a picture I took to easily compare the two (V2 on left, V1 on right)