I am importing an Excel spreadsheet into a web page using the PHPExcel libraries:
$objWriter = PHPExcel_IOFactory::createWriter($objPHPExcel, 'HTML');
$objWriter->save('php://output');
it works but it overrides my page background to white. Every other element on the page it’s formatted correctly according to my CSS but not the background. Any idea?
The default background for an Excel cell is white, so you probably want to change that. I don’t know where you’re setting the page background in the first place, unless you’ve modified the HTML Writer to do so, or changed it in the Excel file (you don’t indicate which); but try setting a default cell background for the worksheet: