For a crying towel? To clean up the blood after they get beat up? No its to let the other emo’s know how they swing.  So what color do you wear?

Handkerchief code or hanky code (also known as bandana code and flagging) is a way of indicating, usually among gay male casual sex-seekers or BDSM practitioners in the leather subculture in the United States, Canada and Europe, whether they are a top or bottom, and what kind of sex they are seeking, by wearing cotton color-coded handkerchiefs (bandanas), usually in the back pocket. Hanky code was widely used in the 1970s as a gay code, however it is increasingly mainstream.

Today the bandanas are worn almost exclusively in the rear pocket, on the left side of the body for tops and on the right for bottoms, just as tops wear their keys on the left belt loop and bottoms on the right. In the past bandanas were also worn tied around the neck (with the knot positioned on either the left or right side); around the ankle (when wearing boots or when undressed); hung from the left or right side of the belt, or on other parts of the body.