Background color depending on value

def get_bgcolor(self, index):
        """Background color depending on value"""
        if index.column() == 0:
            color = QColor(Qt.lightGray)
            color.setAlphaF(.05)
        elif index.column() < 3:
            color = QColor(Qt.lightGray)
            color.setAlphaF(.2)
        else:
            color = QColor(Qt.lightGray)
            color.setAlphaF(.3)
        return color