@property
    def rgb(self):
        color = self._color
        if color is None:
            return None
        if color.val == ST_HexColorAuto.AUTO:
            return None
        return color.val
tabText=None now means insert a spacer, pushed out at 100%
dataset/ETHPy150Open python-openxml/python-docx/docx/dml/color.py/ColorFormat.rgb--crossover with--dataset/ETHPy150Open pyjs/pyjs/pyjswidgets/pyjamas/ui/TabPanel.py/TabPanel.add