POI:set background color for a row or a cell.
use setFillForegroundColor and setFillPattern at the same.
Note that not setFillBackgroundColor.
XSSFCellStyle newstyle = wb.createCellStyle();
newstyle.setFillForegroundColor(IndexedColors.YELLOW.getIndex());
newstyle.setFillPattern(FillPatternType.SOLID_FOREGROUND);
POI:set the last sheet selected, use setActiveSheet method.
XSSFWorkbook wb = new XSSFWorkbook(inputStream); ... wb.setActiveSheet(newExcelCreat.getNumberOfSheets() - 1);