These kids are doing this to get a rise out of people, and probably to piss off some of their black schoolmates. If you scratch under the surface, you'll probably find these kids have neo-Nazi or White Supremacist connections. Their claim that this was some sort of cultural thing is nonsense- this wasn't a meeting of Civil War re-enactors from Charleston.
You might find numerous gangs of militant hispanics and/or blacks who proudly fly (wear) THEIR colors, and these kids, not understanding that it is not permitted for white kids to organize themselves publicly, made a mistake.
If the white kids want to organize themselves for mutual defense, it would behoove them to do it under the table.