如何修复JButton.setBackground(new Color())？Alpha不能正常工作

JButton button = new JButton("Button");
button.setContentAreaFilled(false);
button.setOpaque(true);
button.setBackground(new Color(255, 0, 0, 128)); // 设置半透明背景颜色

import javax.swing.*;
import javax.swing.plaf.basic.BasicButtonUI;
import java.awt.*;

public class CustomButtonUI extends BasicButtonUI {
    @Override
    public void paintBackground(Graphics g, JComponent c, int x, int y, int w, int h) {
        Graphics2D g2d = (Graphics2D) g.create();
        g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f)); // 设置透明度
        g2d.setColor(c.getBackground());
        g2d.fillRect(x, y, w, h);
        g2d.dispose();
    }
}

// 使用自定义的ButtonUI
JButton button = new JButton("Button");
button.setUI(new CustomButtonUI());
button.setBackground(new Color(255, 0, 0, 128)); // 设置半透明背景颜色