def data(self, index, role=Qt.DisplayRole):
        """Cell content"""
        if not index.isValid():
            return None
        if role == Qt.DisplayRole or role == Qt.EditRole:
            return ' '
        if role == Qt.BackgroundColorRole:
            color = self.color_da[index.row(), index.column()].values
            return QtGui.QColor.fromRgbF(*color)
        return None