Horizon In Sunset

At one time or another, all of us have stopped to stare at a beautiful sunset with its red and orange colors. You can take in a colorful sunset anywhere you go, but some parts of the world, like deserts and tropics, are well known for their splashy palette of colors. Why is it that the sky looks like it's bleeding when the sun goes down? And why are some parts of the world more colorful than others?