Sunrise and sunset provide some of the most beautiful sights in the sky. But we only usually bother to look towards the rising or setting sun, and not in the opposite direction, and so we miss some interesting effects.
My photo below was taken at 4pm this evening, facing east.
You can see that a band of sky, and a small stray cloud above, is illuminated by the pink rays from the setting sun in the opposite part of the sky, and that below the pink band there is a blue-grey one, which I think is the shadow of the earth on the atmosphere.
The effect would be more striking given a flatter horizon and a better camera than the one on my phone, but all the same I was pleased to get this shot.