Why are water bottle caps always blue? There's a more logical reason behind the color choice than you might think.

The reason why water bottle caps are blue: Psychologically, it evokes "cleanliness" and "trust"; Visually, it gives a feeling of "coolness" and "freshness"; It is one of the most suitable pigments for food; Over time, it has become the "seafood standard".

So this little blue cap is actually the combined product of science, psychology, and marketing strategy.