The shy is not blue due to the colour of the sea and reflecting its colour. Another false belief of why the sky is blue is that the light scatters off dust in the air. These are not be true, as the sky over the middle of a desert or jungle has the same hue as the sky over the middle of an ocean.

Molecules in the air scatter blue light which is at the lowest end of the electromagnetic spectrum (shorter wavelengths), more than red light which is at the higher end of the electromagnetic spectrum (longer wavelengths).

As light moves through the atmosphere, most of the longer wavelengths pass straight through. So little of the red, orange and yellow colours at the lowest end of the spectrum our affected by the air and pass straight trough, so we visably see more of the shorter wavelenghts of light being, Violet, indigo and blue. The actual visible colour of the sky does depend on where you are in the world and the type of 'air' it has.e gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky. Whichever direction you look, some of this scattered blue light reaches you. Since you see the blue light from everywhere overhead, the sky looks blue.

Isaac Newton was the first person to discover that white light was made up of various colours by the use of a prism. Using a prism he split white light into red, orange, yellow, green, cyan, and blue; then he joined the two ends of the colour spectrum together to show the natural progression of colours. Isaac Newton also associated each colour with notes on a musical scale.