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.
Those are great colors. Distant objects may appear to be more blue due to atmospheric perspective.
Interesting...is that why the sky can be different shades of blue at certain times?
Blue
Blue is one of the three primary colours of pigments in painting and traditional colour theory, as well as in the RGB colour model. It lies between violet and green on the spectrum of visible light. The eye perceives blue when observing light with a dominant wavelength between approximately 450 and 495 nanometres. Most blues contain a slight mixture of other colours; azure contains some green, while ultramarine contains some violet. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering.
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