g a snapshot
        of *color_list* at registration.

        Parameters
        ----------
        name : str
            The name for the color sequence.

        color_list : list of colors
            An iterable returning valid Matplotlib colors when iterating over.
            Note however that the returned color sequence will always be a
            list regardless of the input type.

        z0 is a reserved name for a builtin color sequencez# is not a valid color specificationN)