[timcederman]

Venous blood isn't blue.

[zahlman]

> Veins close to the surface of the skin appear blue for a variety of reasons. The factors that contribute to this alteration of color perception are related to the light-scattering properties of the skin and the processing of visual input by the visual cortex, rather than the actual colour of the venous blood which is dark red.[6]

Huh, thanks.

[thaumasiotes]

As another commenter mentions, there is no blue food. (Though technically plants can be blue.)

Eyes can't be blue either.