We keep experimenting with different dough recipes. I personally don't like any with coloring. Food coloring stains and gets into carpet and I don't buy those instant beverage powders called for in some recipes. So we do natural beige. I am sure if you had natural food colorings it would work well.
I keep playing with the recipe too - A has texture issues, so to speak, so anything that leaves a residue is a no go, so I add a little more flour to ours (not as malleable). For us we still use other types of packaged soft doughs, but love making our own several times a year. The boys measure and stir the ingredients (but of course I do the stove stuff).
Homemade Playdough, (not edible)
1 c. flour
1 c. of water
1/2 c. of salt
2 tablespoons Cream of Tarter
1 tablespoon of Oil
Cook the ingredients until it forms a blob in the pan. Pour/scrape it out onto a plate or pan. Cover with damp cloth and let it cool down. Then it is ready to play with! Store it in the fridge in an airtight container.