code: function(e, el, prop) {
              var val = el.value;
  
              if (prop !== this.OPT.HEX) {
                  val = parseInt(val, 10);
              }
  
              if (val !== this.get(prop)) {
                  this.set(prop, val);
              }
          }
docs: Use the value of the text field to update the control
  @method _useFieldValue
  @param e {Event} an event
  @param el {HTMLElement} the field
  @param prop {string} the key to the linked property
  @protected