Scrotal Rainbow 

A scrotum with pubic hairs of different colors.

"His ball sack has many black pubes and a few red hairs. This is what I call a scrotal rainbow."

Scrotal Rainbow by David Loveless March 9, 2004

drink the rainbow 

sit back and toke/ possibly do acid

dude, you are too up tight, sit back and drink the rainbow

drink the rainbow by Kyle Manuel September 17, 2005

Pot Calling The Rainbow Black 

A variation on the phrase "pot calling the kettle black" that is used when the person being accused by the "pot" is not guilty of the thing they are being accused of while the "pot" is.

Origin: Rainbows are many colors but never black.

Transphobic Cult Leader: Stop indoctrinating children.
Trans Person: Seems like a case of the pot calling the rainbow black.

Pot Calling The Rainbow Black by Shugunou June 14, 2023

Dirty rainbow 

when you are standing above a girl who is lying down and you blow ur load in her face while shitting on her tummy

Yo i just dirty rainbowd that girl

Dirty rainbow by nickyflo March 28, 2009

Dirty Rainbow 

The act of sticking you whole hand up someones asshole, then pulling it out and smearing it on them, openhanded, in a semi-circle pattern to resemble a rainbow. Similar to a dirty sanchez, but this is much bigger and can be done on other parts of the body.

Hey man, I just gave your sister a dirty rainbow.... Then I shot her my pot of gold.

Dirty Rainbow by T-Roc86 December 18, 2009

Mrs. Rainbow 

Lindsay Lohan and/or being very colorful, radiating a similar positive vibe, generating smiles.

Originally she was refered to as Lindsay "Rainbow" Lohan because her fans imagined that's what she would smell like (like a rainbow). But since 'rainbow' can also be used to describe her appearance - in it being very colorful and radiating a similar positive vibe, generating smiles and so on, she quite simply became Mrs. Rainbow - a person able to bring colors into our lives and positive vibes into our hearts.

Mrs. Rainbow by Rooster Fitdse November 6, 2008

Triple Rainbow 

Such intense amounts of joyous orgasmical ecstasy that it makes Double Rainbow feel like torture
Refer to Double Rainbow

Johnson: Dude I just saw Inception yesterday.
Randolf: Oh yeah? How was it?
Johnson: Dude.... TRIPLE RAINBOW!!!!11!!1

Triple Rainbow by BOYETCHLES July 20, 2010