'Return an array (Nv, 4) of vertex colors.
If indexed==\'faces\', then instead return an indexed array
(Nf, 3, 4).'

def vertexColors(self, indexed=None):

    if (indexed is None):
        return self._vertexColors
    elif (indexed == 'faces'):
        if (self._vertexColorsIndexedByFaces is None):
            self._vertexColorsIndexedByFaces = self._vertexColors[self.faces()]
        return self._vertexColorsIndexedByFaces
    else:
        raise Exception("Invalid    indexing    mode.    Accepts:    None,    'faces'")
