, this phrase had two meanings, both of which are no longer current
as of August 2000
In NASCAR, Jeff Gordon's pit crew was called the Rainbow Warriors, after the paint job on the hood of Gordon's #24 car sponsored by DuPont. Some believed that this crew, under the leadership of crew chief Ray Evernham, was primarily responsible for Gordon's success, saying that the car was tuned so perfectly that a trained monkey could have driven it to victory lane; that's a bit unfair to Gordon, but it is true that his performance has dropped off recently. Evernham left in late 1999 to head up Dodge's re-entry into NASCAR; the rest of the Rainbow Warriors jumped ship to Dale Jarrett's team at the end of the '99 season, where, alas, the red and blue paint job of the #88 doesn't lend itself to a cool nickname.
In late July 2000, it was announced that the University of Hawaii's athletic teams would no longer be called the Rainbow Warriors (or Rainbows/Bows for short), but rather just the Warriors. This move coincided with a complete redesign of the school's athletic logo and uniforms. One reason for the redesign was, of course, to make money; the other reason bothered many politically correct organizations.
You see, the rainbow is a symbol commonly used by gay groups, and the association of the rainbow with this team was affecting recruiting and team morale. It seems that most UH athletes didn't want to be thought of as gay, and neither did prospective UH athletes that the school's coaches were trying to recruit from high schools.
It's disturbing that the athletes would think a simple nickname would brand them as homosexuals (of course, in recruiting, you're dealing with high schoolers, and high school minds). But, at the same time, the reaction of liberal groups to this was also disturbing, accusing UH of intolerance because they changed the name to avoid association with gay causes.
It isn't intolerance. (If you can't tolerate gays, you won't last long in Hawaii anyway.) It's a brutally pragmatic decision, getting a barrier to athletic success out of the way, with the side effect of generating a whole bunch of merchandise sales to boot.