Mix everything together in a pot. Heat on low to medium-low while stirring constantly. The mixture will go from runny to thick. When it stops sticking to the sides of the pot and sticks to itself, it is done. Remove from heat, turn out on to the counter, let cool.
If you want to make more than 1 color, don’t add food coloring until after cooled. Then simply separate the batch into equal sized balls and kneed in the food coloring.
The picture above is from a single batch. We separated it into 8 balls (roughly 2 ounces each) and added color. My fingers were a mess and had to be washed repeatedly. And, yes, I know there are only 7 colors in the picture. The red ball was already missing when I went to take the picture. I didn’t bother to hunt it down. Life as a parent…