The moonbow color palette by artist LizCrimson.

A night rainbow glows on a starry night in Hawaii.

A night rainbow in the mountains.

Just as there are rainbows during the day, there can be moonbows at night.  It must be raining opposite the moon and the moon must be nearly full and it can't be any higher than 42 degrees in the sky.  It also has to be dark.  All those factors combined together make for this atmospheric phenomenon to be fairly rare.

A moonbow in the high desert of California.  "The requirements needed to form a 'moonbow' are similar to the requirements of the much more common rainbow -- moonlight rather than sunlight is the light source. Look very closely and perhaps you can see faint star trails between the clouds in this 30 second exposure."

A night rainbow (nachregenbogen in German) in Hammelburg, Germany. "Driving through the fog on this spring evening, my headlight beams created this high arching fogbow. Fogbows are more feebly colored than their Sun illuminated counterparts (rainbows) and usually appear whitish to the unaided eye."

A night rainbow over Waimea Canyon.

A moonbow stretching over Salt Pond Bay in St. John, Virgin Islands.

"It is December, winter in Egypt. Evening there comes early, at five o'clock the sun already slides for horizon. And right after a decline, especially in the winter, the sky is painted in gentle colors of a rainbow."

A night rainbow over South Anchorage.

A fiberoptic mural at the Phoenix Children's Hospital in Phoenix, illustrates a rare night rainbow emerging under a moonlit sky.

A moonbow by Kenna Graff.

Bringers of the night rainbow.

A moonbow over the trees.

A neon night rainbow, and an incandescent one.

Speaking of rainbows ... is this where they come from?