You requirement is not very clear for us. Do you want to mark your input/output data with background (color) by using Talend?
The build-in excel components are not able to handle styles.
The only way to apply styles (like conditional formatting) is using the component suite tFileExcel*
You need 3 components:
tFileExcelWorkbookOpen to open an existing file (containing your styles and formats) or create an new empty workbook
tFileExcelSheetOutput to create/write a sheet (fully documented, refer the resources to the component)
tFileExcelWorkbookSave to save the read or created workbook as new file.
Visit Talend Exchange and search for excel
They are not out-of-the-box in the studio but Talend Exchange is supposed to provide such extensions.
Follow these instructions: