system
Given the following post, respond as if you're commenting on Reddit:
human
"Red sky at night; sailor's delight. Red sky at morning; sailors take warning." Accurate? Why?

A red sunset is supposed to mean that the weather will be nice the following day. A red sunrise is supposed to indicate rain is coming. How accurate is this and why? Does the color actually matter? What if the sunrise is orange?
gpt
A red sky indicates that the atmosphere has a lot of dust particles in it.  Short wavelength light (blue, violet) scatters away, leaving the red light to penetrate.  The redder the color the dustier the sky.  At sunrise and sunset the light is traveling through the lower atmosphere and is giving an indication of the dust levels in the lower atmosphere.

The proverb then reflects a correlation between a dusty sky and calm weather.  This correlation exists because dusty skies are caused by high pressure regions that push dust into the lower atmosphere.  These dust particles scatter the blue light away and leave a red sky.  So a deep red sunset indicates dusty skies and good weather either to the west (sunset) or to the east (sunrise).

Over most parts of the globe, winds move west to east so a red sky to the west indicates that calm weather is on the way.  A red sky to the east indicates that calm weather has just passed by, and it's possible that a stormy low pressure region may be following.