Will a juror be held in contempt if they refuse to answer a question during voir dire?

LovesTheConstitution is right. I would just add that the judge is the referee of the courtroom in a sense; if the questioning was really uncalled for he would probably speak up himself. It is safe, however, to speak your mind in such a case, if you feel that it is right. If the judge has a problem with that, he'll tell you very clearly that you have to answer the question. He won't just slap you with contempt right away. You also won't be automatically excused for being uncooperative. I think it would increase your chances of one of the lawyers not liking you, though.