If you do a web search for “skittles drugs,” you will find that it’s slang for several different kinds of drugs.
Or, there’s this entry from the Urban Dictionary:
skittles party
a party where a bunch of teenagers or young adults get together with a lot of random pills.usually taken from parents medicine cabinets.
they put them all into a pile and every one takes a few.
you dont know exactly what you take.
hey! since there is nothing to do tonight..lets all raid our medicine cabinets and have a skittles party!!
we will get messed up!
I had always thought that skittles was a tabletop game, sort of like bowling, in which a ball is used to knock down pins.