There are some variations of Lean. For example, Promethazine and Codeine syrup is usually Purple in color. But there are other colors of syrup that work the same way. There is a golden colored syrup (hydrocodone based) and other colors as well.
Lean slows you down. It makes you feel good. It's meant to be sipped on, and it taste damn good. One of the best feelings you will ever experience. Euphoria with a hint of sedation.
John: I can't man.
Chris: Why not?
John: I'm sipping on that lean already bro. Don't need that alcohol.
Chris: Fuck that, gimme some!