Blue is a great color, and one of the three primary colors 
Blue is a fantastic color! And it's actually my favorite color as well.
It's awesome, it lies between violet and green on the light spectrum
Ohh interesting! Blue comes in lots of different shades though. I'd say my favorite is either Navy Blue or Baby Blue.
An optical effect called Tyndall scattering explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective.
Blue has been an important colour in art and decoration since ancient times. The semi-precious stone lapis lazuli was used in ancient Egypt for jewellery and ornament and later, in the Renaissance, to make the pigment ultramarine, the most expensive of all pigments. In the eighth century Chinese artists used cobalt blue to colour fine blue and white porcelain. In the Middle Ages, European artists used
blue.
The normal primary and secondary hues in tanzanite are blue and violet. Untreated tanzanite is a trichroic gemstone, meaning that light that enters this anisotropic crystal gets refracted on different paths, with different color absorption on each of the three optical axes. As a result of this phenomenon, a multitude of colors have been observed in various specimens: shades of purple, violet, indigo, blue, cyan, green, yellow, orange, red and brown. After heating, tanzanite becomes dichroic. The dichroic colors range