title: tkinter GUI quiz that uses buttons for answers
body: <p>I am writing a quiz in python tkinter  and when the user click on the answers if the answer is wrong the correct answer text color is changed to green I got that working but when I add the disable function so the user can't answer the question again it's not showing the correct answer in green. </p>
  
  <pre><code>def check(self, guess):
      #compares the guess to the correct answer
      print ("guess " + guess)
      correct = self.problems[self.counter].correct
      print ("correct " + correct)
      self.btnA.config(state='disabled')
      self.btnB.config(state='disabled')
      self.btnC.config(state='disabled')
      self.btnD.config(state='disabled')
      if guess == correct:
        #update ans
        if guess == "A":
           self.astatus["text"] = "✓"
        elif guess == "B":
           self.bstatus["text"] = "✓"
        elif guess == "C":
           self.cstatus["text"] = "✓" 
        else:
           self.dstatus["text"] = "✓"
        self.marks+=10
  
      else:
        if guess == "A":
           self.astatus["text"] = "x"
        elif guess == "B":
           self.bstatus["text"] = "x"
        elif guess == "C": 
           self.cstatus["text"] = "x"
        else:
           self.dstatus["text"] = "x"
  
  
        if correct == "A":
           self.btnA["fg"] = 'green'
        elif correct == "B":
           self.btnB["fg"] = 'green'
        elif correct == "C": 
           self.btnC["fg"] = 'green'
        else:
           self.btnD["fg"] = 'green'
  </code></pre>