GH Work or PT came out in 2007. Bal stopped making PT with feet since 2008 F/W, but Giant Work has feet all the time. If you want a Giant Part Time, you only have 2007 S/S, 2007 F/W and 2008 S/S to choose from.
Among those three seasons, the blues have Aquamarine, French Blue and Electric Blue. My guessing the one you saw was Electric Blue with SGH. That is the most beautiful stand out blue combo Bal ever made IMO.