CNN's website has an excellent article on racial segregation in churches. It examined a lot of the nitty-gritty dynamics in churches with multiple ethnic groups, and how it can be like tip-toeing through a minefield as you try not to offend anyone.

The article mentions how black churches can prefer to remain mostly black, just as white churches may prefer to remain white. It mentioned how some sensitive black preachers have toned down their preaching style, knowing that whites sometimes cringe under traditional too-fiery preaching. Very interesting stuff.

My denomination, in the US, is close to lilly white. Until a few years ago (when they pulled out over petty disagreements), we had white churches in California that shared buildings with Hispanic church plants. The Hispanics were growing, the whites shrinking. But the whites pulled shenanigans to hold onto their power. It was sad, some of the stories I heard.