Mix together powdered sugar and whipped frosting. Play dough will be sticky at first, but continue to add more powdered sugar until you reach a desired consistency and your play dough is no longer sticky.
Separate play dough into as many sections as you'd like for different colors. Add one section of play dough to a bowl and add 5-10 drops of food coloring. Mix play dough with your hands until the color is consistent. Add more food coloring for a deeper, darker color. Repeat with additional colors to other sections of play dough.
Store play dough in air tight container or ziploc bag.
Notes
Add more powdered sugar if play dough ends up too sticky.