Why toothpaste tubes have colored marks: myth vs. reality

A claim circulating online suggests that the colored stripe found on toothpaste tubes — blue, green, red or black — indicates what the product contains. According to this theory, a black mark supposedly means the toothpaste is entirely synthetic and should be used no more than once a week, while a green stripe allegedly signals a fully natural, safe-to-use-daily formula.

This explanation, however, is inaccurate. Manufacturers add these colored marks for an entirely different reason: to help automated production equipment function correctly.

How the tubes are actually made

Toothpaste tubes are produced on conveyor systems that shape tubes from a multilayer strip of material, then cut and seal them. For the cutting mechanism to know precisely where one tube ends and the next begins, a contrasting colored mark is printed on the strip, which a sensor detects. The machine cuts and seals the material exactly at that mark.

The color is chosen specifically to contrast with the tube's own color, minimizing the chance of a cutting error. A dark green tube, for instance, might use a white or red mark, while a white tube could use green, blue, red or black. Sometimes the mark's color happens to match the packaging design, but this is purely a manufacturing coincidence, not an indicator of ingredients.

Similar contrasting marks appear on other tubed products too, such as shampoos, creams and facial cleansers. When such a mark is absent, it usually means a different type of equipment was used, one that doesn't require a contrasting mark to cut the material.