@classmethod
def show(cls, sublist='all'):
    """
        Returns a list of the color names

        :param: str sublist: (default='all') options 'colors'/'core'/'neutral'/'all'

        :returns: a list of color names
        :rtype: list

        """
    if sublist is not None:
        if sublist not in ['core', 'neutral', 'colors', 'all']:
            raise Exception(
                'List type can only be "core", "neutral", "colors", or "all"')
    list_ = []
    for color in getattr(cls, sublist):
        list_.append(color)
    return list_
