code: function(e, el, prop) {
              var command = this._getCommand(e);
              if (command === 6) { // return, update the value
                  this._useFieldValue.apply(this, arguments);
              }
          }
docs: Handle keydown on the hex field
  @method _hexFieldKeypress
  @param e {Event} the keypress event
  @param el {HTMLElement} the field
  @param prop {string} the key to the linked property
  @protected