i am using aspose.total 17.3 version
Below is code:-
Workbook xlsReport = new Workbook(FileFormatType.Excel97To2003);
Worksheet sheetXls = xlsReport.Worksheets[xlsReport.Worksheets.ActiveSheetIndex];
sheetXls.AutoFitColumns();
sheetXls.Name = "Data";
Style titleStyle = xlsReport.CreateStyle();
titleStyle.Font.Size = 10;
titleStyle.Font.IsBold = true;
titleStyle.HorizontalAlignment = TextAlignmentType.Left;
titleStyle.VerticalAlignment = TextAlignmentType.Left;
titleStyle.ForegroundColor = System.Drawing.Color.Blue;
titleStyle.Pattern = BackgroundType.Solid;
Row row1 = xlsReport.Worksheets[0].Cells.Rows[0];
// Initialize styleflag object.
StyleFlag flag = new StyleFlag();
// Set all formatting attributes on.
flag.All = true;
// Apply the style (described above)to the range.
row1.ApplyStyle(titleStyle, flag);
// Modify the style (described above) and change the font color from red to black.
titleStyle.Font.Color = System.Drawing.Color.Black;
titleStyle.Update();
Thanks