You said site in one of your posts.
But I get where ya going.
Do it. Forget these "naysayers" and that includes your co-workers.
But however, DO not. I repeat DO NOT. Make it known that the site is only for "black people." If you want to target that market, just let the forum be; and in the "about section" (a lot of forums have them, some don't), and in that section "[site name here] was founded to unite the black gaming community together in one forum to connect gamers of [insert ethnicity here]..."
I'm trying not to use "black" in that sentence, but if you could say it better than I, please replace "black" with whatever fits that area well - because it's sort of offensive. Sure, they're black, but you could offend a "black" person just calling them out as "black."