无法使用hightlightbackground更改tkinter顶级上的按钮颜色

Question

Below is a working example of the problem. You press the first button and the top-level opens with non colored button. Thanks!

import tkinter as tk
class MainGui:
    def __init__(self,root):
        self.root=root
        self.main_frame=tk.Frame(root)
        self.button1=tk.Button(self.main_frame,text='open top level',
        highlightbackground='green',command=self.open_top,font=  
        ('helvetica',24))
        self.button1.grid(row=0,column=0)
        self.main_frame.grid(row=1,column=1)
    def open_top(self):
        class TopLevel:
            def __init__(self,root):
                self.root = root
                self.top_frame = tk.Frame(root)
                self.button2 = tk.Button(self.top_frame, text='not   
                colored',highlightbackground='green', font=
                ('helvetica', 24))
                self.button2.grid(row=1,column=1)
                self.top_frame.grid(row=1,column=1)

        root=tk.Toplevel()
        app=TopLevel(root)
root=tk.Tk()
app=MainGui(root)
root.mainloop()

Answer 1

The colors appear correctly when clicking off the gui or in other words somewhere else on desktop. Clicking on the gui results in colors going back to grey