'Background color depending on value'

def get_bgcolor(self, index):

    if (index.column() == 0):
        color = QColor(Qt.lightGray)
        color.setAlphaF(0.05)
    elif (index.column() < 3):
        color = QColor(Qt.lightGray)
        color.setAlphaF(0.2)
    else:
        color = QColor(Qt.lightGray)
        color.setAlphaF(0.3)
    return color
