如何让tkinter按钮在每次单击时都更改颜色

import tkinter as tk
import random

def change_color():
    # 生成随机的RGB颜色值
    r = random.randint(0, 255)
    g = random.randint(0, 255)
    b = random.randint(0, 255)
    color = '#%02x%02x%02x' % (r, g, b)
    
    # 更改按钮的背景颜色
    button.config(bg=color)

# 创建主窗口
window = tk.Tk()

# 创建按钮并绑定函数
button = tk.Button(window, text='Click Me', command=change_color)
button.pack()

# 进入主循环
window.mainloop()