Changing background colour of jFreeChart

ChartPanel inherit method javax.swing.JComponent.setBackground(java.awt.Color)

chartPanel.setBackground( Color.RED );

Or try:

chart.getPlot().setBackgroundPaint( Color.BLUE );

See documentation of JFreeChart.getPlot() and Plot.setBackgroundPaint()

See this post on SO or this one too.

You have to use JFreeChart.getPlot().setBackgroundPaint(Color.WHITE); like this:

public static void main(String[] args) {
    DefaultPieDataset pieDataset = new DefaultPieDataset(); 
    pieDataset.setValue("LoggedIn" +": "+ 5, 10);
    pieDataset.setValue("LoggedOut" +": "+ 8, 17);
    JFreeChart jfc = ChartFactory.createPieChart("title", pieDataset, false, false, false );
    jfc.getPlot().setBackgroundPaint(Color.WHITE);
    ChartPanel chart = new ChartPanel(jfc);
    JFrame frame = new JFrame();
    frame.add(chart);
    frame.pack();
    frame.setVisible(true);
}   

I hope it helps!