In a large saucepan, melt the butter over low heat. Add the mini marshmallows and stir until completely melted and smooth. Remove from heat.
Add the Rice Krispies cereal to the melted marshmallow mixture and stir until well coated.
Divide the mixture into three equal portions. In separate bowls, melt the red, white, and blue candy melts according to package instructions.
Once melted, mix one portion of the Rice Krispies into each bowl of candy melts, stirring until evenly coated.
Line a 9x13 inch baking dish with parchment paper. Press the red Rice Krispies mixture into the bottom of the dish evenly.
Next, layer the white Rice Krispies mixture on top of the red layer, pressing down gently. Finally, add the blue Rice Krispies mixture on top of the white layer, pressing down to create an even surface.
Allow the mixture to cool at room temperature for about 30 minutes. Once set, cut into squares.
Before serving, sprinkle the top with red, white, and blue sprinkles for an extra festive touch.