Looked through a few pages, this one I think explains it fairly well https://demos.smu.ca/index.php/demos/astronomy/35-red-sunsets https://demos.smu.ca/index.ph

Looked through a few pages, this one I think explains it fairly well https://demos.smu.ca/index.php/demos/astronomy/35-red-sunsets https://demos.smu.ca/index.php/demos/astronomy/35-red-sunset... The answer it gives is more of a combination of what I thought and what the parent said, tl;dr version: scattering both due to just normal oxygen and nitrogen composition of the air and also pollutants (which I think dust would also qualify, though most things I could find that specified were talking more about sulfur compounds).