Override default colours 

@@ -22,6 +22,7 @@
     title              => 'Product Sales',
     y_label            => 'Units Shipped (Millions)',
     x_label            => 'Product Sales by Year',
+    dclrs              => ['#ff782a', '#6daa3a', '#4d7296'],
 ) or die $graph->error;
 
 $graph->set_legend(@products);