You haven't shown us what you have tried, which means it's harder to guide you. A general rule is that ANYTHING that can be done on the face of the spreadsheet (i.e. excluding VBA) can be done from Perl via Win32::OLE. You might want to have a look at Re: pie chart color -- Win32::OLE for some code where I set up & then play around with a chart. Each workbook has a charts collection. If you know the index of the chart you want, you can point to it with something like $wb->charts($index) and then add or change the settings at your whim.

Regards,

John Davies