'A member of :ref:`MsoThemeColorIndex` or |None| if no theme color is
specified. When :attr:`type` is `MSO_COLOR_TYPE.THEME`, the value of
this property will always be a member of :ref:`MsoThemeColorIndex`.
When :attr:`type` has any other value, the value of this property is
|None|.
Assigning a member of :ref:`MsoThemeColorIndex` causes :attr:`type`
to become `MSO_COLOR_TYPE.THEME`. Any existing RGB value is retained
but ignored by Word. Assigning |None| causes any color specification
to be removed such that the effective color is inherited from the
style hierarchy.'

@property
def theme_color(self):

    color = self._color
    if ((color is None) or (color.themeColor is None)):
        return None
    return color.themeColor
