originally meaning LSD(according to dictionaries and drug resources)
more recently redefined and popularized in refference to purple cannabis.
Both usages are correct, however it is more commonly used in refference to cannabis.
... also a popular song by Jimi Hendrix written under the influence of LSD...
I'm bangin with my hand up her dress like, unh
I'll make her cum, purple haze in my lungs"-THE GAME (f/ 50 Cent) LYRICS This Is How We Do
"Purple haze all in my eyes
Don't know if it's day or night
You got me blowin', blowin' my mind
Is it tomorrow, or just the end of time?" - Jimi Hendrix Lyrics Purple Haze
"Are You Experienced, one time I just heard that recently, I must have been high or something. Yeah, when I heard it, it was like, um, I said, 'Damn! I wonder where my head was at, when I said all those things,' you know. But I don't consider that more invention of psychedelic, 'cause it's asking a lot of questions. I said, 'Damn! Wait a minute, I feel ... you know, 'scuse me while I do this,' for a second maybe, it could be stuff like goin' in different strange areas and all this, like most curious people do. And I just happened to put it on "Purple Haze." But the way I write things, I just write them in, with a clash between reality and fantasy mostly... ALTHAM: Well, I think psychedelic to most people has connotations with LSD.
HENDRIX: Oh, you mean strictly LSD? You mean with that type of consciousness?
ALTHAM: Yeah, with dreams...
HENDRIX: Oh right! Oh yeah, well you have to give them a little bit of it to dream on, because so they can hear it over again, 'cause they might be in a different mood. Well, dreams come from different moods. So it's nothin' but moody... you know laughs." -Keith Altham Interview with Jimi Hendrix 1970