Ernest Sichak, age 14  for his question:

What causes the orange colors of sunset?

The sun is actually blazing white in a black velvet sky. Its sunbeams reach us through a gauzy veil of atmosphere. Tiny particles of gas, dust and debris in the atmosphere play tricks on the sunbeams of white light and force them to show their true rainbow colors. Each colored ray travels on its own wave length. The rays at the red end of the spectrum have the longer wave lengths. The blue rays at the opposite end have the shorter wave lengths.

The blue rays of light are bent and scattered. as the sunbeams come come straight down through perhaps a thousand miles of atmosphere, When the sun is low at dawn and sunset, the sloping sunbeams have a much longer journey through the air. The rays with longer and longer gave lengths are bent and scattered. At sunset, the deep‑blue evening sky is often painted with dazzling blends of yellow, orange and red.