import tkinter
from tkinter import *

class MyApp:
	def __init__(self, parent):
		self.myParent = parent  ### (7) remember my parent, the root
		self.myContainer1 = Frame(parent)
		self.myContainer1.pack()
		
		self.button1 = Button(self.myContainer1)
		self.button1.configure(text="OK", background= "green")
		self.button1.pack(side=LEFT)	
		self.button1.bind("<Button-1>", self.button1Click) ### (1)
		
		self.button2 = Button(self.myContainer1)
		self.button2.configure(text="Cancel", background="red")   
		self.button2.pack(side=RIGHT)
		self.button2.bind("<Button-1>", self.button2Click) ### (2)
		
	def button1Click(self, event):    ### (3)
		if self.button1["background"] == "green": ### (4)
			self.button1["background"] = "yellow"
		else:
			self.button1["background"] = "green"
	
	def button2Click(self, event):  ### (5)
		self.myParent.destroy()     ### (6)

		
root = Tk()
myapp = MyApp(root)
root.mainloop()