The sky is blue because of a phenomenon called **Rayleigh scattering**. When sunlight enters the Earth’s atmosphere, it produces different colors, each corresponding to a different wavelength. Blue light has shorter wavelengths and gases and particles are more scattered in all directions than other colors such as yellow or red

It is the scattered blue light we see when we look at the sky. At sunrise and sunset, there is less sun in the sky and more light must pass through the sky. The shorter blue waves scatter from the field of view, making the longer waves red and orange, so the sky reflects those colors at those times