title: How to get rid of widget border?
body: <p>I have the following code:</p>
  
  <pre><code>from Tkinter import *
  def gui():
      root = Tk()
      root.configure(background = 'red')
  
      rightPanel = PanedWindow(borderwidth=0, bg='black')
      rightPanel.pack(side = 'right', fill=BOTH, expand=1)
  
      canvas1 = Canvas(rightPanel, bg='black')
  
      rightlabel = Label(canvas1, bg= 'grey')
      rightlabel.place(relx=0.5, rely=0.5, anchor=CENTER)
  
      canvas1.pack(fill=BOTH, expand=1)
      root.wm_attributes('-topmost', 1)
      mainloop()
  
  if __name__ =='__main__':
      gui()
  </code></pre>
  
  <p>As  you can see if you run it (especially in fullscreen mode), there is grey border near window edge.
  It looks like border of PanedWindow widget (you can see it, if you set its <code>fill=NONE</code> and expand window). Note that ts borderwidth is set to 0</p>
  
  <p>How can I get rid of it or set it to some color?</p>