sata cable color means nothing. if there is an official sata cable color specification, then it's certainly not adhered to. I have 3 different colored sata cables sitting unused; blue, grey, and red (all came with motherboards, I never bought an a sata cable by itself).
the cables that are marketed at "sata2 cables" are most likely a newer revision, higher quality cable. the newer revision adds a locking mechanism to the connectors themselves (a nice improvement, but has no effect on transfer speeds) and better shielding.
from what I have read, sata/sata1/sata150 cables should work on a sata2/sata300 drive. the newer revision cables are a little better, but have little or no effect on transfer speeds.
cheers :wave: