Rainbow

A rainbow is an optical and meteorological phenomenon caused by precipitation in an atmosphere having a prismatic effect upon white light (typically from a sun), and creating the appearance of an arc of color through the sky.

In Irish legend, a leprechaun's pot of gold was to be found at the end of a rainbow's arch. The inhabitants of holographic old-Irish village Fair Haven mentioned rainbows. 

The 1960s Earth band Berman's Rainbow Dreamers took their name from the rainbow, alluding to its multi-colored nature in their psychedelic imagery and aesthetic. 

Two songs performed by Vic Fontaine featured rainbows in the lyrics: It's Only a Paper Moon and I've Got the World on a String.