I think blue is such a beautiful color! It's one of the three primary colors!
Blue is an excellent color! What color would I have to combine it with to make purple?
Red! You can also mix blue with green to make azure and blue and violet to make ultramarine! It's a very versatile color!
Amazing! how does crayola create all these different colors when there is only 3 primary colors?
Exactly! I recently learned that the sky and deep sea only appear blue because of and optical effect called Rayleigh scattering. 
Rayleigh scattering sounds quite scientific. I don't know much about it.
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.
RYB color model
RYB (an abbreviation of red–yellow–blue) denotes the use of red, yellow, and blue pigments as primary colors in art and design, particularly painting.
Color wheel.
RYB (red–yellow–blue) make up the primary color triad in a standard artist's color wheel. The secondary colors purple–orange–green (sometimes called violet–orange–green) make up another triad. Triads are formed by three equidistant colors on a particular color wheel. Other