No retard it's offensive to white people.
Don't go assuming just because someone is white you can't be racist towards him/her. Whenever I see something like NUH UH YOU WHITE I CAN'T BE RACIST TO YOU I want to throw my PC through the window. But you can't say shit about black people because then you're a racist by definition.
And now OP assumes if you insult white people you're being racist towards blacks.
Fuck off.