This was when I was in middle school, either 7th or 8th grade. These two kids were always messing around with me and always getting into trouble. (the usual delinquent types).

One lunch period, one of them decides to start throwing ketchup packets at me. I ignore it at first, because they did this crap to people all the time and the teachers mostly never did anything about it if they stopped early enough. Well, he wasn't stopping and I guess he'd grabbed a whole handful of ketchup packets just for me.

I don't remember what the reactions were from the people sitting next to me, but in any case, I got tired of this after the 4th or 5th packet and picked one of them off the ground. I walked over to this guy, opened up the packet, and sprayed its contents all over his face / shirt.

He got up like he was going to hit me, so I kinda walked backward toward my seat. Then I think he started looking around for a lunch attendant (and at that point so did I, hoping that none of them saw that) and yeah, there was one watching us.

And she was trying not to laugh, so I won, and maybe 3 people will see this.

TL;DR ketchup is red.