"Artificial colorants" are chemicals that are added to food, drinks, or products to give them a specific color. They are made in a laboratory and are not naturally found in the item itself. Full definition
Green poop remedy is possible by avoiding food items mixed with artificial colorants, junk foods and green leafy vegetables. (primehealthchannel.com)
This is the same organization that says artificial colorants are okay in foods, the same colorants that cause my six year olds face to go red and blotchy (among other reactions that the medical community will try to say aren't related, because food doesn't affect behavior they say). (ecochildsplay.com)
Therefore, we are pleased to announce that we have significantly reduced the number of artificial colorants in our PEDIGREE ® Dry Recipes, and we continue to explore future alternative recipe improvements. (pedigree.com)