title: How can I get a Tkinter widget attribute?
body: <p>I create a Button, and set its callback, but how can I get the attribute of the button like <code>fg</code>?</p>
  
  <pre><code>from Tkinter import *
  
  def callback(self):
      tkMessageBox.showinfo("button", color)
  
  top = Tk()
  frame = Frame(top)
  frame.pack()
  
  greenbutton = Button(frame, text="Brown", fg="brown", command=callback)
  greenbutton.pack( side = RIGHT )
  
  bluebutton = Button(frame, text="Blue", fg="blue", command=callback)
  bluebutton.pack( side = LEFT )
  
  top.mainloop()
  </code></pre>
  
  <p>I just want when I click the button blue and it will tell me it is blue.</p>