Create a spread sheet with custom styles using Open XML DSK

spreasheet.cs

using (SpreadsheetDocument document = SpreadsheetDocument.Create("somefile.xls", SpreadsheetDocumentType.Workbook))
                {
                    WorkbookPart workbookPart = document.AddWorkbookPart();
                    workbookPart.Workbook = new DocumentFormat.OpenXml.Spreadsheet.Workbook();
                    WorksheetPart worksheetPart = workbookPart.AddNewPart<WorksheetPart>();

                    WorkbookStylesPart sp = workbookPart.AddNewPart<WorkbookStylesPart>();
                    sp.Stylesheet = new DocumentFormat.OpenXml.Spreadsheet.Stylesheet();
                    Stylesheet stylesheet = sp.Stylesheet;
                    stylesheet.Fonts = new DocumentFormat.OpenXml.Spreadsheet.Fonts();
                    stylesheet.CellFormats = new DocumentFormat.OpenXml.Spreadsheet.CellFormats();



                    Font font = new Font(new DocumentFormat.OpenXml.Spreadsheet.FontSize() { Val = 11 }, new DocumentFormat.OpenXml.Spreadsheet.Color() { Rgb = HexBinaryValue.FromString("4b53cb") }, new DocumentFormat.OpenXml.Spreadsheet.Bold());


                    Font font2 = new Font(new DocumentFormat.OpenXml.Spreadsheet.FontSize() { Val = 15 }, new DocumentFormat.OpenXml.Spreadsheet.Color() { Rgb = HexBinaryValue.FromString("c93653") }, new DocumentFormat.OpenXml.Spreadsheet.Italic());
                    stylesheet.Fonts.Append(font);
                    stylesheet.Fonts.Append(font2);

                    DocumentFormat.OpenXml.Spreadsheet.Fill fill = new DocumentFormat.OpenXml.Spreadsheet.Fill() { };
                    DocumentFormat.OpenXml.Spreadsheet.PatternFill patternFill = new DocumentFormat.OpenXml.Spreadsheet.PatternFill() { PatternType = PatternValues.Solid };
                    DocumentFormat.OpenXml.Spreadsheet.BackgroundColor backgroundColor = new DocumentFormat.OpenXml.Spreadsheet.BackgroundColor() { Rgb = HexBinaryValue.FromString("ed5976") };
                    DocumentFormat.OpenXml.Spreadsheet.ForegroundColor foregroundColor = new DocumentFormat.OpenXml.Spreadsheet.ForegroundColor() { Rgb = HexBinaryValue.FromString("ed5976") };

                    patternFill.Append(backgroundColor);
                    patternFill.Append(foregroundColor);

                    fill.Append(patternFill);
                    stylesheet.Fills = new Fills();
                    stylesheet.Fills.AppendChild(fill);

                    DocumentFormat.OpenXml.Spreadsheet.Border border2 = new DocumentFormat.OpenXml.Spreadsheet.Border();

                    DocumentFormat.OpenXml.Spreadsheet.LeftBorder leftBorder2 = new DocumentFormat.OpenXml.Spreadsheet.LeftBorder() { Style = BorderStyleValues.Thin };
                    Color color1 = new Color() { Indexed = (UInt32Value)64U };

                    leftBorder2.Append(color1);

                    RightBorder rightBorder2 = new RightBorder() { Style = BorderStyleValues.Thin };
                    Color color2 = new Color() { Indexed = (UInt32Value)64U };

                    rightBorder2.Append(color2);

                    DocumentFormat.OpenXml.Spreadsheet.TopBorder topBorder2 = new DocumentFormat.OpenXml.Spreadsheet.TopBorder() { Style = BorderStyleValues.Thin };
                    Color color3 = new Color() { Indexed = (UInt32Value)64U };

                    topBorder2.Append(color3);

                    DocumentFormat.OpenXml.Spreadsheet.BottomBorder bottomBorder2 = new DocumentFormat.OpenXml.Spreadsheet.BottomBorder() { Style = BorderStyleValues.Thin };
                    Color color4 = new Color() { Indexed = (UInt32Value)64U };

                    bottomBorder2.Append(color4);
                    DiagonalBorder diagonalBorder2 = new DiagonalBorder();

                    border2.Append(leftBorder2);
                    border2.Append(rightBorder2);
                    border2.Append(topBorder2);
                    border2.Append(bottomBorder2);
                    border2.Append(diagonalBorder2);

                    stylesheet.Borders = new Borders();

                    stylesheet.Borders.Append(border2);
                    CellFormat cellFormat1 = new CellFormat() { FontId = 0, FillId = 0, BorderId = 0 };
                    CellFormat cellFormat2 = new CellFormat() { FontId = 1, FillId = 0 };
                    CellFormat cellFormat3 = new CellFormat(new Alignment() { Horizontal = HorizontalAlignmentValues.Center, Vertical = VerticalAlignmentValues.Center }) { FontId = 1, FillId = 0 };

                    stylesheet.CellFormats.Append(cellFormat1);
                    stylesheet.CellFormats.Append(cellFormat2);
                    stylesheet.CellFormats.Append(cellFormat3);
                    stylesheet.Save();

                    SheetData sheetData = new DocumentFormat.OpenXml.Spreadsheet.SheetData();
                    MergeCells mergeCells = new MergeCells();
                                      workRow.Append(CreateCell("Expenses", 0));
                     
   
                    sheetData.Append(workRow);
  
                    worksheetPart.Worksheet = new Worksheet(sheetData);
                    worksheetPart.Worksheet.Save();
 
                    Sheets sheets = workbookPart.Workbook.AppendChild(new Sheets());

                    Sheet sheet = new Sheet() { Id = workbookPart.GetIdOfPart(worksheetPart), SheetId = 1, Name = "Trial" };


                    sheets.Append(sheet);


                    workbookPart.Workbook.Save();

                }