title: Setting plot area background color in JPGraph
body: <p>It seems that <code>$graph-&gt;SetColor('red');</code> doesnt't really do anything (from JPGraph's example0.html:</p>
  
  <pre><code>&lt;?php // content="text/plain; charset=utf-8"
  require_once ('jpgraph/jpgraph.php');
  require_once ('jpgraph/jpgraph_line.php');
  
  // Some data
  $ydata = array(11,3,8,12,5,1,9,13,5,7);
  
  // Create the graph. These two calls are always required
  $graph = new Graph(350,250);
  $graph-&gt;SetScale('textlin');
  $graph-&gt;SetColor('red'); #        &lt;---- this does nothing 
  // Create the linear plot
  $lineplot=new LinePlot($ydata);
  $lineplot-&gt;SetColor('blue');
  
  // Add the plot to the graph
  $graph-&gt;Add($lineplot);
  
  // Display the graph
  
  $graph-&gt;Stroke();
  ?&gt;
  </code></pre>
  
  <p>What am I missing?</p>