A "rainbow party" is supposed to be a party where girls wear different shades of lipstick and suck a guy off. In actuality, it is a term invented by Oprah and no teen had heard of it until her show in 2004.
Oprah invented rainbow parties so parents can lock up their teens and send them to boarding school.
By C
In the US, it is apparently a euphemism (or media-invented myth)for rather lewd naughtiness (see all other definitions). In the UK, it means jelly, ice-cream and dressing-up as Zippy, Bungle, Geoffrey, George, Rod, Jane or Freddy and singing "The Wheels on the Bus". The latter seems condusive to a much more satisfying experience.
Yank: Dude, I'm so emotionally crippled and shallow, I went to this badass Rainbow Party last night. Now I feel even more empty and my dick's kinda itchy. Limey: I say, old bean, I had a Rainbow Party last week! We all had a beezer time, despite Bungle having eaten too much jelly and ice-cream.
By chris wheelie
A gathering where many girls wear different colors of lipstick. Each girl proceeds to give a blowjob to the boy or boys that are attending the "party." The color of lipstick that the girl giving head was wearing then rubs off onto the boys dick. After every girl at the party gives the boy head and all of their lipstick rubs off onto his dick, the penis ends up with what appears to look like a rainbow of colors on it. (The girls at this party are usually classified as sluts/skanks/whores)
guy 1: "Dude. This rainbow party is bitchin'!" guy 2: "Hey man, do you know where the girl wiht the red lipstick is? she'll complete my rainbow" guy 1: "Yea that smut is over there blowing some other guy."
By a premiscuous girl
When a young group of teenagers goes to a party and each girl wears a different colored lipstick. Then all the boys line up and each girl proceeds to "go down" on the boys. The girl with her lipstick farthest down on the most boys is deemed "winner"
"'Mom! My throat is too sore from last night's rainbow party!' 'It's ok, sweety, you can stay home from school today'"
By NicoleCousins
its a party where oral sex is given to guys, there are multiple girls and they all where different colored lipstick and they all leave their color on the guy. hence the rainbow
By Bea