In a large mixing bowl, stir together gluten free flour, salt, and cream of tartar.
1 cup all-purpose gluten free flour, 1/4 cup salt, 1 tsp cream of tartar
In another bowl, combine boiled water and oil. They will separate but that's okay.
1/2 cups boiled water, 1 tbsp olive oil or coconut oil
Pour the water and oil mixture over the flour mixture, and stir with a wooden spoon until a dough forms.
Use your hands knead into a ball. If the dough is too dry, you can add a bit more water. If it's too wet, add more flour until it reaches the right consistency. Transfer to a parchment or wax paper.
Parchment or wax paper
Knead with your hands a few more times, then divide the dough equally into the number of colors you want to create.
Make a dent in the center of each dough, then add 5-6 drops of food coloring to start. Knead until the color is fully incorporated (this can take a bit of time), adding more for a bolder hue. Since you are adding moisture with food coloring, you may need to add a little bit more flour if the texture gets too sticky.
Food coloring
Store in a resealable plastic bag or an airtight container at room temperature. If the playdough gets too moist or too dry during storage, you can fix the consistency with more flour or water.
Resealable plastic bag or airtight container