title: ffmpeg screencapture with xvfb displaying green screen
body: <p>Using xvfb to run a browser window and want to do a screen recording of that Doing </p>
  
  <pre><code>xvfb-run Firefox http://google.com
  ffmpeg -y -r 30 -f x11grab -i :94.0 output.mp4
  </code></pre>
  
  <p>Getting output as if colors are washed out</p>