Place marshmallows and butter in a large microwave-safe bowl, heat in the microwave in 30 second intervals, stirring until it is fully melted and smooth.
Add in cereal, mix until combined. Add in green food coloring, and mix until it is fully green. Add in the m&ms, and sprinkles.
Press the mixture into a greased baking dish. Refrigerate for at least 20 minutes. Cut into bars.