

- The colour theory: Purple toothpaste uses colour theory to make teeth appear whiter. Since purple cancels out yellow on the colour wheel, it helps neutralize yellow tones, creating a temporary brightening effect.
- Innovation & Marketing: Consequently, the choice of purple in toothpaste can be seen as an application of novelty aiming to boost its market presence
- Psychology: The colour purple is often associated with luxury and sophistication, which can appeal to a certain market segment.


- Certain medications
- Dental trauma
- Long-term habits like smoking
- Brown, gray, or blue discoloration
- Stains from coffee, tea, or internal injury
