In a large pot combine flour, salt and cream of tartar. Stir until combined. Next add in the water and oil.
Cook over medium heat, stirring constantly. Stir the playdough until it thickens and begins to form into a ball. Remove pot from heat. Place the dough into a bowl. Let cool until you can touch it.
Knead it until smooth.
Time to add the colors! Divide dough into the amount of colors you want. Place dough balls into quart size resealable bags.
Drop about 5-6 colors of food coloring into the dough, seal the bag and knead the dough until the color is evenly distributed. Add more color if you want it more vibrant.
Store play dough inside the bags to keep it soft for up to 3 months.