Packaging details—like the circles on chip bags and the symbols on cosmetics labels—can be mystifying to the average consumer. For years, a graphic has circulated the internet claiming to explain the hidden meaning behind the colored markings on the bottom of toothpaste tubes. While it's true that those color codes are there for a reason, the reason is much less interesting than the online rumors suggest.
According to Snopes, a widely-shared image on social media alleges that the colors on the seams of toothpaste tubes correlate to certain types of ingredients. The picture shows four different colored markings, with green meaning natural, blue indicating natural and medicine, red meaning natural and chemical composition, and black signifying pure chemical.
This "decoding" isn't based in truth, however. The markings on toothpaste packaging have nothing to do with the ingredients inside the tube—and even if they did, classifications like natural and chemical are too vague to mean anything. The real reason the colors are there is to aid the machinery responsible for putting the packaging together. The tiny colored rectangles are actually called eye marks or color marks, and they tell light beam sensors where a tube needs to be cut or folded. Once the toothpaste reaches the store, the markings no longer serve a purpose.
If you do want to know more about the ingredients in your toothpaste, it's not as hard as deciphering a mysterious code. "Oral care companies don’t mark their toothpastes with colored squares to try to trick consumers and hide ingredients from them," Colgate writes on its website. "If you want to know what kind of ingredients your toothpaste has, don’t look for a colored block at the end of the tube. Instead, take a look at the packaging for a comprehensive list of ingredients."
You can find the ingredients in your toothpaste listed on the outer box and/or the tube itself—and you don't need to know any secret codes to read them.