Although brought up in the Matrix Movie, as one who won't wake up from reality, the blue pill on the streets has come to mean just that. The blue pill is a painkiller, usually oxy/roxycodeine pills that keep you in your world of illusion, taking the pain away from the realities of life. It's codeine, tar, powder, hard - anything that keeps your mind at bay.
John Doe: Let's kick it, it's a blast party!
Jane Doe: Sure lol, you want the red or blue baby?
John Doe: Haha .. always the blue pill
Roxy: I need to function, can't take this depression no more
Xany: I thought you always came through?
Roxy: Yeah but it's getting worse, like if I don't get more my bones are gonna break through my skin
Xany: well you can count on me to bring you down
Roxy: I sure can, maybe after my next shakes (found blue pills)