Spray 2 large bowls with cooking oil and evenly divide popcorn between them, set aside.

Melt 4 Tbsp. butter in a medium saucepan over low heat. Add 3 cups marshmallows and stir until melted. Add 4-6 drops (or more to reach desired color) of red food coloring and stir until combined.

Pour marshmallow mixture over 1 bowl of popcorn and gently stir until coated. Allow mixture to cool slightly before spraying hands with cooking oil and rolling popcorn mixture into six 1 cup balls about the size of a softball. Repeat process with the remaining popcorn, butter and marshmallows using green food coloring.

Place popcorn balls on a baking sheet and allow them to cool. Wrap each one in plastic and store at room temperature for up to 1 week.