As the sun begins to set, it appears lower in the sky. This means the light must travel through a thicker layer of atmosphere to reach your eyes. Along this longer path, most of the shorter blue and violet wavelengths are scattered out and away. What remains are the longer wavelengths—red, orange, and pink.

These warmer colors are less scattered and can survive the long trip through the sky. That’s why the sun looks redder and the whole sky may glow with orange and pink hues. The more particles and pollution in the air, the more intense the colors can be, especially during hazy or dusty evenings.

Sunsets feel peaceful and romantic partly because of this beautiful color transformation. It’s nature’s way of saying goodbye to the day—filtering light through the atmosphere and giving us a fiery masterpiece before night falls.