Farting Rainbows 

Meaning to be happy or excited in a sarcastic way.

Example 1 - I am so happy, I am farting rainbows

Example 2 - gee... your not having fun, because I am farting rainbows over here.

Farting Rainbows by kjj5hf October 27, 2009

Farting Rainbows 

To have a nice smelling fart.

Felicia:"OMG I was farting rainbows the other night because of those fruit smoothies!"
Lakeisha:"OMG gurl, at least it wasn't a nasty one."

Farting Rainbows by Princess_Felicia July 28, 2016

farting rainbows and unicorns 

When someone is so head-over-heels in love with someone that they believe their own previously toxic flatulence has been magically transformed into something inordinately wonderful.

Ever since I first laid eyes on her I’ve been farting rainbows and unicorns!

farting rainbows and unicorns by Dr Bunnygirl May 19, 2021

Rainbow farting

Another term for virtue signaling. Spewing comments that indicate an idealistic personality on a mission ready to bombard message boards and social media with a perceived problem of which you don't fully understand the complications and nuances. You do however feel the need "to do something" about it and leave your mark for future generations in your ceaseless efforts to make the world a better place.

She kept rainbow farting comments on the message boards about social problems that mostly existed in her mind or only got it from hearsay and what the media reported.

Rainbow farting by Erik-Jan Tytgat August 25, 2022