Remove kernels from popcorn and place in a large mixing bowl.

Melt butter over medium heat in a large pan. Add the marshmallows and turn heat to medium low. Cook and stir till marshmallows are melted and mixture is completely smooth. Remove from heat and stir in the vanilla.

Pour the mixture over the popcorn and stir till well coated. Stir in the Skittles.

With wet hands, form the popcorn mixture into balls. Set on waxed paper to cool.