title: How to change the background color for tix.Balloon message?
body: <p>I've been pulling my hair out for this one...</p>
  
  <p>I've configured my tkinter app to use tix, so that I can leverage the Balloon widget for tooltips.  However, the balloonmsg that pops up is a very hideous yellow, and for the life of me I can't figure out how to set the background color.  Here's what I've tried so far:</p>
  
  <pre><code>b = tix.Balloon(self, statusbar=self.status,bg='grey87',initwait=500)
  b.subwidget('label')['bg'] = 'grey87'
  b.subwidget('message')['bg'] = 'grey87'
  </code></pre>
  
  <p>This config has only resulted in this:</p>
  
  <p><img src="https://i.stack.imgur.com/PUaUf.png" alt="enter image description here"></p>