There is an easy way to discriminate on race without asking about race (aside from the obvious) -- pay. Lower the pay enough and only certain races (those at a competitive disadvantage in the job market) will apply.

At my previous employer, there were some positions with salaries so low that the only people who applied were foreigners who were so desperate that they were willing to take it. White Americans (and American-born Indian Americans for that matter) with computer science degrees simply had more options than to take such a terrible role at such a terrible salary. It had nothing to do with the company discriminating.