Sassy Grass / Green Go was the high-impact green entry in Chrysler's 1970–1971 paint program — distinct from Sublime (FJ5 in 1970, GK6 in 1971), which is a lime green. Sassy Grass is darker and more saturated, closer to a clean meadow green than to a citrus.
1970 used the F-prefix code FK2; the 1971 reorganization to G-prefix codes renamed it GF7. Same color, two codes depending on year. 1972 was the last year, in very small numbers — the high-impact program contracted hard for 1972 as insurance and emissions pressure squeezed the muscle market.
The Plymouth name 'Sassy Grass Green' carried better; the Dodge name 'Green Go' was meant to evoke the stoplight-go sense and got mixed reception. Today the two names are used interchangeably; the order sheet of the day used whichever marque was on the dealer's lot.