Combine all ingredients in a medium saucepan.
Food coloring is optional at this stage, but it's MUCH easier to achieve consistent coloring if you add it in at the same time as the water.
Over medium high heat, stir all ingredients continuously. After a few minutes, the playdough will start to thicken and become hard to stir. Try to keep stirring (or flipping) the playdough to achieve even heat.
Remove from heat when no longer sticky. Set aside to cool.
When the playdough is cool enough to touch, knead for 1-2 minutes until your playdough is soft and pliant.