To catch the rainbow means to achieve the impossible, figuratively.
Finally, I have caught the rainbow! *Insert thing you have achieved*.
I will catch the rainbow with this project I'm making!
A soccer skill only performed by high level players, the ball is flicked up and kicked over the performer's head, dazzling and terrifying onlookers.
Soccer Fan: Holy shit, he just did a rainbow kick and got a shot off from it.
Other Soccer Fan: That's my team!
When a male inserts his own penis into his asshole and bouncing up and down, creating a reversed rainbow
I was very lonely so I gave myself a Reversed Rainbow.
This is when people of the gay community swap cum, usually two guys that snowball each other.
Wow those two guys were so gay, you know that at the end of the night they were totally rainbow swapping right?
When someone wears different colored clothing, usually one or two colors per each item of clothing. Some people refer to 'rainbow goth' as a style. Even the hair color can refer to 'rainbow goth'. Tattoos and/or piercings also refer to 'rainbow goth'.
"I saw a rainbow goth at that anime convention last week."
A type of kink involving vomit. Could be inducing barfing or playing with barf.
I have lots of kinks but Rainbow Play isn't one of them