evidence: There’s also a colored bar on the bottom of toothpaste tubes. Some claim that the color of this bar means a great deal about the toothpaste’s ingredients. Nonetheless, like a lot of stuff floating around on the internet, the claim about these color codes is completely false. The color on the bottom of your toothpaste means absolutely nothing about the ingredients, and you shouldn’t use it to help you decide on a toothpaste. A fake consumer tip about the color codes of toothpaste tubes has been circulating the internet for quite some time. According to the tip, you should be paying close attention to the bottom of your toothpaste tubes. There’s a small colored square at the bottom and the color, be it black, blue, red, or green, allegedly reveals the ingredients of the toothpaste: