Sassy Grass / Green Go was the high-impact green entry in Chrysler's 1970–1971 paint program — distinct from FJ5 (Sublime / Limelight), which is a luminous citrus-lime. FJ6 is darker and more saturated, closer to a clean meadow green than to a citrus.
1970 used the F-prefix code FJ6; 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.
Per Dodge Garage's high-impact retrospective, Dodge sold the color as 'Sassy Grass' and Plymouth sold it as 'Green Go'. Dealer order sheets of the day used whichever marque was on the lot; today the two names get used interchangeably in collector conversation but the build documentation tracks the marque. Earlier Plenum versions had this pair attributed in reverse and to a different code (FK2); the slug is retained as paint-fk2 for backward link compatibility.