Why do sunsets and the subsequent afterglow often feature reds and oranges?

Answer

Longer-wavelength light scatters less intensely through the long atmospheric path

When the Sun is low or below the horizon, the light travels a very long path through the atmosphere; shorter blue wavelengths are scattered away, allowing the less scattered, longer wavelengths (oranges and reds) to persist and reach the observer.

Why do sunsets and the subsequent afterglow often feature reds and oranges?
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