修改TextField ---- PlaceHolder顏色（屬性）

var attributes:[String:AnyObject] = NSMutableDictionary() as! [String:AnyObject]

      attributes[NSForegroundColorAttributeName] = UIColor.white

 let paceH:NSAttributedString = NSAttributedString.init(string: "請輸入手機號！", attributes: attributes)

        Phonefiled.attributedPlaceholder = paceH