如何在QTreeWidget中替换空白颜色？

from PyQt5.QtWidgets import QApplication, QTreeWidget, QStyledItemDelegate, QStyleOptionViewItem, QTreeWidgetItem
from PyQt5.QtGui import QColor, QPainter

class CustomDelegate(QStyledItemDelegate):
    def paint(self, painter, option, index):
        # 获取单元格的数据
        text = index.data()

        # 判断单元格是否为空白
        if not text:
            # 设置自定义的空白颜色
            option.palette.setColor(QPalette.Base, QColor(255, 0, 0))  # 这里使用红色作为示例颜色

        # 调用父类的绘制函数绘制单元格
        super().paint(painter, option, index)

app = QApplication([])

# 创建QTreeWidget并设置委托
tree_widget = QTreeWidget()
tree_widget.setItemDelegate(CustomDelegate())

# 添加树形结构数据
root = QTreeWidgetItem(tree_widget, ['Root'])
child1 = QTreeWidgetItem(root, ['Child 1'])
child2 = QTreeWidgetItem(root, ['Child 2'])
child3 = QTreeWidgetItem(root, ['Child 3'])

# 设置空白项
child2.setText(0, '')  # 设置Child 2的内容为空

tree_widget.show()
app.exec()