evidence: It goes on the claim that coloured markings on the bottom on toothpaste tubes show if the "paste is made out of organic substances or not". Supposedly a black line means the toothpaste contains "only chemicals", a red line indicates "chemicals and natural substances" and a blue line means "natural substances and drugs". Toothpastes with "all-natural ingredients" will be marked with a green line. [...] Colgate recommends that you talk to your dentist if you are concerned about your toothpaste or the ingredients in it.