When you need to take several different London underground lines to get to your destination rather than the usual one due to either breakdowns, engineering works etc. Like taking the Victoria, Central, Piccadilly, Jubilee and Circle & District (making it blue, red, navy, silver, yellow and green)
I had to a right 'Rainbow Ride' into work today on the tube today - I had to change trains 4 times!
When a number of women put on a different shade of lipstick each and all take turns blowing a guy, mixing the colors creating a "rainbow" like appearance on the man's crouch, therefore a "Rainbow Ride".
Last night Jenn, Colleen, and Stina put put on blue, yellow, and red lipstick and gave me a rainbow ride.