How to change color palette
https://demo.phpcontrols.com/public/demo/?ctrl=chart
Find the "Multiple Bar Colors" demo, the series color can be set
$pc->set_series_color(array('#85802b', '#00749F', '#85802b', '#85802b', '#85802b'));
$pc->set_series_color(array('#85802b', '#00749F', '#85802b', '#85802b', '#85802b'));