Aurora Borealis

what color are they?

The aurora is most often seen as a striking green, but it also occasionally shows off other colors, ranging from red to pink or blue to purple.

Aurora borealis over trees and a river, made up of green, yellow, pink, and purple. The colors reflect into the river.

Oxygen at about 60 miles up gives off that green-yellow color.

A bright green aurora borealis curving above a snowy place.

Nitrogen in different forms produces the blue and red-purple light.

A tall and thin green, red-purple, and blue-ish colored aurora borealis stretching up into the sky from trees.