How to use the clu.constants.polyfills.numpy.uint8 function in clu

def ColorType(name, *args, **kwargs):
    global color_types
    dtype = numpy.dtype(kwargs.pop('dtype', numpy.uint8))
    if name not in color_types[dtype.name]:
        channels = split_abbreviations(name)
        
        class Color(namedtuple(name, channels)):
            
            def __repr__(self):
                return "%s(dtype=%s, %s)" % (
                    name, self.__class__.dtype.name,
                    ', '.join(['%s=%s' % (i[0], i[1]) \
                        for i in self._asdict().items()]))
            
            def __hex__(self):
                return '0x' + "%x" * len(self) % self
            
            def __int__(self):
                return int(self.__hex__(), 16)