The people redefining language so as to remove meaning are the racists, and the idiots that fall for their crap, who would have you believe that a bigot with institutional power is the same as a bigot with no power.
Everything in your life is a reflection of a choice you have made. If you want a different result, don't blame someone else, or expect others to make a change, you should stop complaining and make a different choice. Remember, the circumstances of your birth don't determine the outcome of your life.
It's a general question, but I'll paint a hypothetical scenario for you. A sole proprietor (one individual) contract software developer places a notice on his website that he will not do business with any redheaded customers.Can you narrow to better define the circumstances in your proposed scenario? However, the actor in your proposed scenario being me as an individual is inaccurate to the topic of this thread. I would propose that you not involve the individual as the antagonist or protagonist in your question. For example, businesses are not individuals nor do they have the certain rights that individuals have. That may change depending on how the Hobby Lobby case at the SCOTUS turns out. And given that the Citizens United case came down as it did, then that distinction may not be as clear cut as it once was, although that case dealt only with the First Amendment as it pertains to monetary donations to political campaigns.
Do you feel as if you have the right to violate the person or property of this individual in order to coerce him into doing business with redheads?