title: A right background color of a button with tkinter?
body: <p>I've stablished a background color in a button with Tkinter, but when I click into the button then the background color changes to the system color, in my case windows 8.1. Is there any way to fix that?
  The code:</p>
  
  <pre><code>compute = tk.Button(rframe, text='Equals', command=comp_s, relief='flat', font=MY_FONT, background='blue', foreground='white')
  compute.pack(side='left')
  </code></pre>
  
  <p>I'm using Python 3.4.2 64 bits</p>
  
  <p>Thanks!</p>