What does waring rainbow clothes mean?

It might not necessarily mean anything, though it has become a stereotype in many people showing their pride today through rainbow clothing. I wouldn't jump to conclusions that everyone who wears rainbow is automatically homosexual. People have their own certain styles, and even though "rainbow being oh so gay" is a way the media has set people to look at things today, some people honestly will not care what other people think, and wear what they find appealing to them, even with the set stereotypes on the apparel.