You can certainly do it with JavaScript. Not sure what you tried previously. Suppose you put a CSS class on your radio button ApprovalRB. Then the following code should work:

$(document).ready(function(){
  $('.cf-collection-block').on('click','.ApprovalRB input[type="radio"]',function(){
    switch($(this).val()){
      case "Approved":
        $(this).closest('div.form-q').css('background-color','green');
        break;
      case "Rejected":
        $(this).closest('div.form-q').css('background-color','red');
        break;
      default:
        $(this).closest('div.form-q').css('background-color','transparent');
        break;
    }
  });
});

A couple of notes here. First, it is important to use a delegated event handler in this case [ .on(event, selector, function) ] so that you handle events for any row in the collection that may be added after the page loads. Second, this doesn't override the default highlighting applied to the actively selected field, so it may look a little strange / partially-highlighted the moment you click the radio button. You could change that too if you wanted.