Mix together the flour, cornstarch, oil, and lemon juice.
Mix together the food coloring into 1 cup of warm water.
Slowly pour the water into the flour mixture, stirring as you pour. Stir until combined, then knead with your hands until the flour is completely absorbed.
Allow to cool and add more flour if the dough is too sticky.
Repeat process for whichever colors you want to make.
Notes
You can use any vegetable oil, but we recommend coconut oil, or at least something non-GMO.