Вызов функции в функции

#рабочий кусок
from tkinter import *
def change():
    if var.get() == 0:
        l['bg'] = 'blue'
    elif var.get() == 1:
        l['bg'] = 'red'
    elif var.get() == 2:
        l['bg'] = 'white'
    elif var.get() == 3:
        l['bg'] = 'black'
        l['fg'] = 'white'
   
root1 = Tk()
l = Label(root1, text = "темы")
var = IntVar()
var.set(3)    
r1 = Radiobutton(root1, text = "синяя", value=0, variable = var)
r2 = Radiobutton(root1, text = "красная", value=1, variable = var)
r3 = Radiobutton(root1, text = "белая", value=2, variable = var)
r4 = Radiobutton(root1, text = "черная", value=3, variable = var)
i = Button(root1, text = "изменить", command = change)    
l.pack()
r1.pack(anchor = W)
r2.pack(anchor = W)
r3.pack(anchor = W)
r4.pack(anchor = W)
i.pack()
root1.mainloop()
/
/
#нерабочий кусок
from tkinter import *
 
root = Tk()
mainmenu = Menu(root)
root.config(menu = mainmenu)
 
def ex():
    root.destroy()
    
def par():
    def change():
        if var.get() == 0:
            l['bg'] = 'blue'
        elif var.get() == 1:
            l['bg'] = 'red'
        elif var.get() == 2:
            l['bg'] = 'white'
        elif var.get() == 3:
            l['bg'] = 'black'
            l['fg'] = 'white'
        
    root1 = Tk()
    l = Label(root1, text = "темы")
 
    var = IntVar()
    var.set(3)
    
    r1 = Radiobutton(root1, text = "синяя", value=0, variable = var)
    r2 = Radiobutton(root1, text = "красная", value=1, variable = var)
    r3 = Radiobutton(root1, text = "белая", value=2, variable = var)
    r4 = Radiobutton(root1, text = "черная", value=3, variable = var)
    i = Button(root1, text = "изменить", command = change)
    
    l.pack()
    r1.pack(anchor = W)
    r2.pack(anchor = W)
    r3.pack(anchor = W)
    r4.pack(anchor = W)
    i.pack()
    root1.mainloop()
 
 
filemenu = Menu(mainmenu, tearoff=0)
filemenu.add_command(label="Выход", command = ex)
 
mainmenu.add_cascade(label="Файл", menu=filemenu)
mainmenu.add_cascade(label="Настройки", command = par)
 
root.mainloop()