The following example shows how to customize cell appearance in the exported document when you export the Pivot Grid to XLSX (or XLS) format. In this example, custom appearance settings (the azure background and italic font) are applied to the cells that correspond to the Pivot Grid's data area.
Handle the PivotXlsxExportOptions.CustomizeCell or PivotXlsExportOptions.CustomizeCell event to customize cell appearance in the exported document.
Use the e.ExportArea property to identify the cell location in the exported Excel document. The e.Formatting property sets the cell format.
WinForms - How to Print a Document that Contains Pivot and Chart Controls