It's not possible to say whether Richards was wrong for his rant. Marzutra is right. We need to know the context. And we probably never will.
Like Chaim often points out, we have the right to fight back when certain segments (be they Blacks, Arabs, or even Jewish leftists) try to harm us. We have a right to point out that so many Blacks are robbing and raping Whites. We have a right to protest racist Affirmative Action policies. We can speak out against Black leaders and their followers who attack Jews, and encourage and celebrate the murder of Jews. And In Richards' case, he has the right to fight back if the guy called him a cracker, or said he had no talent, 'cause he's White.
But let's assume for the moment that Richards was not provoked.
I can't say it's OK to attack Blacks just because they're Black. Never mind that it's wrong (we can argue about that forever), but it's just plain dumb. Also it's no different than those who hate Jews because we're Jews.
What if a Black man chooses to be a Righteous Gentile, and observe the seven Hoahite Laws, and worship the G-d of Israel, and stand in support of G-d's People? You cannot attack such a person because his skin is black.
As far as dating Black women: If you prefer White women over Black women there's nothing racist about it. It's no different than finding blondes more attractive than brunettes. On the other hand, there's nothing wrong with a White Jewish man dating a Black Jewish woman (I would), and vice versa.
By the way...
Whatever you think about Richards, watch over the next few weeks, and compare how he gets treated with how Mel Gibson was treated. And remember, Richards was yelling in a fit of anger, and probably didn't mean what he said. Gibson got drunk and said what he meant (but had never dared say when he was sober).