title: Python: How to change the border color of ttk.Checkbutton when it is active?
body: <p>I want to change the bordercolor of the ttk.Checkbutton widget, which is a light blue by default. I tried to use the configure function of ttk.Style() and managed to change the color of the whole button or other things when it is active, but not the border of the Checkbox.
  Additional question is where I could find this kind of information in for example some kind of documentation of all options that can be changed in the ttk style?</p>
  
  <p>Here is an example of what I tried:</p>
  
  <pre><code>from tkinter import ttk
  
  root = Tk()
  
  s = ttk.Style()
  s.configure('MyOwn.TCheckbutton',
      background='white',)
  s.map('MyOwn.TCheckbutton',
         foreground=[('active', 'red')])
  
  cb = ttk.Checkbutton(root,text='Text',style='MyOwn.TCheckbutton')
  cb.pack()
  root.mainloop()
  </code></pre>
  
  <p>I can change the color of the text when i hover over the checkbutton, but I don't find how to change the border color of the Checkbox.</p>