def get_value_tuple(self):
        """
        Returns a tuple of the color's values (in order). For example,
        an LabColor object will return (lab_l, lab_a, lab_b), where each
        member of the tuple is the float value for said variable.
        """
        retval = tuple()
        for val in self.VALUES:
            retval += (getattr(self, val),)
        return retval