This is one of the world’s most frequently pondered questions, and, contrary to what some people believe, the sky’s blue color is not due to the reflection of water. Light from the sun is composed of the spectrum of colors. When sunlight strikes the Earth’s atmosphere, ultraviolet and blue waves of light are the most easily scattered by particles in the atmosphere. So, other colors of light continue to the Earth while blue and ultraviolet waves remain in the sky. Our eyes can’t see ultraviolet light, so the sky appears the only color remaining that we can see, blue.