How can I tell my mother not to play the race card with me?

Tell her the truth. Tell her it is your life and you respect how she feels but you would be happier without kids and with someone of another race. Im the end it is up to you. Maybe she is afraid that she will never have grandchildren and she really wants them. Tell her that not everyone is OJ and that she really shouldn't judge someone that she doesn't know becaus ethats what causes problems in the first place. But most importantly tell her you love her and respect her because she is still your mother and she really does want to help.