The Visible light spectrum is the different colors in the white light that we see. The different colors are red, orange, yellow, green, blue, indigo, and violet. You can see these colors by bending light with a prism or with water. The sky is blue because the molecules (building blocks of the universe) in the atmosphere reflect blue light the most. Some examples of the molecules are Oxygen, Nitrogen, Carbon Dioxide, Methane and many more! These gases reflect the blue color and absorb the other colors.