What causes the colour of a sunset?

The colours of a sunset are caused by the scattering of sunlight by Earth’s atmosphere. As the Sun sets, its light passes through a thicker layer of the atmosphere, scattering shorter wavelengths like blue and violet. This leaves longer wavelengths, such as red, orange, and pink, to dominate the sky. Dust, water droplets, and air pollutants can enhance these colours by scattering light in different ways. The resulting vibrant hues make each sunset unique.