Line a 9X13 inch dish with wax paper, set aside.
Place your rice cereal into a large bowl, set aside.
In a medium sized pot, melt your butter over medium to high heat.
Once melted add the marshmallows, and stir until they are melted.
Remove from the heat and add as much green food coloring as you'd like. Stirring as you go.
Once you have the green color you are looking for, pour the melted marshmallow mix into your bowl of rice cereal.
Stirring with a large rubber spatula until all of the cereal is coated.
Pour into your prepared dish.
Using your rubber spatula, or another sheet of wax paper, press the cereal mix down flat.
Allow to cool and harden.
Once hardened, remove the treats from the dish, by picking up the wax paper.
Cut into whatever sized squares you prefer.
Melt your chocolate chips in a microwave safe bowl for one minute, with the microwave on 50% power.
Stir really well.
Return to the microwave and go for another 30 seconds, on 50% power.
Stir until all the chips are melted.
Dip the bottoms of your cut treats into the white chocolate.
Place on the wax paper and sprinkle with the rainbow sprinkles.
Allow to harden before storing them in an airtight container.