title: Color window in hbrBackground
body: <pre><code>WNDCLASS wc;
  ...
  wc.hbrBackground = (HBRUSH)GetStockObject(COLOR_WINDOW+1);
  </code></pre>
  
  <p>I could not undestand what is <code>+1</code> for and what is <code>HBRUSH</code>?</p>