Green Flash
Sometimes just before a sunset or just after a sunrise, when light interacts with the earth’s atmosphere, you will see a “green flash”. This phenomenon rarely lasts for more than a few seconds so you’d need to be looking that way at the exact moment that it happens.
Photo courtesy of: Brocken Inaglory, CC BY-SA 3.0 https://commons.wikimedia.org/wiki/File:Big\_green\_flash.JPG