It's mentioned in the documentation.
$objRichText = new PHPExcel_RichText(); $objRichText->createText('This invoice is '); $objPayable = $objRichText->createTextRun('payable within thirty days after the end of the month'); $objPayable->getFont()->setBold(true); $objPayable->getFont()->setItalic(true); $objPayable->getFont()->setColor( new PHPExcel_Style_Color( PHPExcel_Style_Color::COLOR_DARKGREEN ) ); $objRichText->createText(', unless specified otherwise on the invoice.'); $objPHPExcel->getActiveSheet()->getCell('A18')->setValue($objRichText);