In a medium saucepan over medium-low heat, melt butter and marshmallows, stirring constantly.

Once completely melted, remove from heat and add green food coloring (to desired color) and vanilla. Stir until the color is blended.

Gently stir in cornflakes, making sure to coat the cereal.

Drop rounded tablespoonfuls onto waxed paper and decorate with red candies. Let stand at least 30 minutes before serving.