The only real solution is to teach children (and adults) to celebrate their differences and individuality, not to try to mould everyone the same.
Celebration of difference is a noble aim, but as Psychotick says above, there are those who want to remain outside the cultural herd, to go against the grain. Or, to put it on your words, the ones who are happy to be teased in the playground. When the cultural norm is diversity/difference (where I believe current trends are heading - though we're not there yet), the idea homogeneity becomes an outlier, an oddity; perhaps ultimately even a cult. And at that point, it could easily adopt a kind of perverse, outré, subversive attractiveness. Which could in turn grow to become the norm again. And so the cycle continues anew.
Piousflea has it right - conflict is written into our code. You could easily even argue it's essential to our development and survival.