代码：
ICellStyle cellStyle = workbook.CreateCellStyle();
cellStyle.BorderBottom = BorderStyle.Thin;
cellStyle.BorderLeft = BorderStyle.Thin;
cellStyle.BorderRight = BorderStyle.Thin;
cellStyle.BorderTop = BorderStyle.Thin;
cellStyle.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center;
cellStyle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center; ICellStyle cellStyleTitle = workbook.CreateCellStyle();
cellStyleTitle.BorderBottom = BorderStyle.Thin;
cellStyleTitle.BorderLeft = BorderStyle.Thin;
cellStyleTitle.BorderRight = BorderStyle.Thin;
cellStyleTitle.BorderTop = BorderStyle.Thin;
cellStyleTitle.VerticalAlignment = NPOI.SS.UserModel.VerticalAlignment.Center;
cellStyleTitle.Alignment = NPOI.SS.UserModel.HorizontalAlignment.Center;
IFont font = workbook.CreateFont();
font.IsBold = false;
font.FontHeightInPoints = ;
cellStyleTitle.SetFont(font);
HSSFPalette palette = ((HSSFWorkbook)workbook).GetCustomPalette();
palette.SetColorAtIndex((short), , , );
var color = palette.FindColor(, , );
//下面两行设置单元格背景色
cellStyleTitle.FillPattern = FillPattern.SolidForeground;
cellStyleTitle.FillForegroundColor = color.Indexed; ICellStyle cellStyleTitle2 = workbook.CreateCellStyle();
cellStyleTitle2.CloneStyleFrom(cellStyleTitle);
font = workbook.CreateFont();
font.IsBold = false;
font.FontHeightInPoints = ;
cellStyleTitle2.SetFont(font);