我想让我的ttk.treeview有交替的颜色

import tkinter as tk
from tkinter import ttk

root = tk.Tk()

style = ttk.Style()
style.configure("Treeview",
                background="#E1E1E1",
                foreground="black",
                rowheight=25,
                fieldbackground="#E1E1E1")
style.map("Treeview",
          background=[("selected", "#347083")])

treeview = ttk.Treeview(root, style="Treeview")
treeview.pack()

# 添加树状结构数据
treeview.insert("", "end", text="节点1", iid="1")
treeview.insert("", "end", text="节点2", iid="2")
treeview.insert("", "end", text="节点3", iid="3")
treeview.insert("1", "end", text="子节点1", iid="4")
treeview.insert("1", "end", text="子节点2", iid="5")
treeview.insert("2", "end", text="子节点3", iid="6")

root.mainloop()