Green’s Dictionary of Slang

(drugs) a variety of LSD that was packaged in bright orange pills.

1971		Current Sl. V:4.
1978		L. Kramer Faggots 301: You name it, somebody’s on it. [...] Blotter, Orange Sunshine, Sweet Pea.
1981		D.E. Miller Bk of Jargon 338: orange sunshine, orange wedges: LSD.
1994		N. McCall Makes Me Wanna Holler (1995) 126: I [...] tried selling chemical drugs — orange sunshine, mescaline, windowpane, purple microdots, quaaludes.
1999		T. Dorsey Florida Roadkill 33: The best drugs from four counties: [...] black beauties, Panama Red, Acapulco Gold, blue cheer, orange sunshine.
2001		ONDCP Street Terms 16: Orange wedges — LSD.