title: Setting plot background colour in Seaborn
body: <p>I am using Seaborn to plot some data in Pandas.</p>
  
  <p>I am making some very large plots (<code>factorplot</code>s).</p>
  
  <p>To see them, I am using some visualisation facilities at my university.
  I am using a Compound screen made up of 4 by 4 monitors with small (but nonzero) bevel -- the gap between the screens. 
  This gap is black.
  To minimise the disconnect between the screen i want the graph backgound to be black.
  I have been digging around the documentation and playing around and I can't work it out..
  Surely this is simple.</p>
  
  <p>I can get grey background using <code>set_style('darkgrid')</code></p>
  
  <p>do i need to access the plot in matplotlib directly?</p>