@classmethod
def _is_valid_color(cls, c):
    """
        Determines if ``c`` is a valid color for a drawing tool.

        Tools accept RGB, HSV, or strings (for named and web colors)

        :param c: a potential color value

        :return: True if c is a valid color value.
        :rtype:  ``bool``
        """
    from .. import colors
    if type(c) in [colors.RGB, colors.HSV]:
        return True
    elif type(c) == str:
        return colors.is_tkcolor(c) or colors.is_webcolor(c)
    return False
