The first IFTs I saw def had the purple decals - that was in late 1992 so maybe officially a 1993 bike, the font on the original downtube decal is definitely 1992 - it was stretched for the 1993 bikes - that is the main giveaway for me.
Of course it should be noted that Marin (and many other manufacturers) commonly deviated from catalogue spec. Marin also commonly made mid-year changes to bikes for instance there are late 1991 bikes with Zolatone paint, but with the Afterburner stays which were a 1992 catalgue addition.
I actually don't ever recall seeing an IFT with green decals and parts.