.NET Excel Library - Excel Conditional Formatting in C#

// Initialize Excel engine and application
using ExcelEngine excelEngine = new ExcelEngine();
IApplication application = excelEngine.Excel;
application.DefaultVersion = ExcelVersion.Xlsx;
IWorkbook workbook = application.Workbooks.Create(1);
IWorksheet worksheet = workbook.Worksheets[0];
// Applying conditional formatting to "A1"
IConditionalFormats condition = worksheet.Range["A1"].ConditionalFormats;
IConditionalFormat condition1 = condition.AddCondition();
// Represents conditional format rule that the value in target range should be between 10 and 20
condition1.FormatType = ExcelCFType.CellValue;
condition1.Operator = ExcelComparisonOperator.Between;
condition1.FirstFormula = "10";
condition1.SecondFormula = "20";
worksheet.Range["A1"].Text = "Enter a number between 10 and 20";
// Setting back color and font style to be applied for target range
condition1.BackColor = ExcelKnownColors.Light_orange;
condition1.IsBold = true;
condition1.IsItalic = true;
// Applying conditional formatting to "A3"
condition = worksheet.Range["A3"].ConditionalFormats;
IConditionalFormat condition2 = condition.AddCondition();
// Represents conditional format rule that the cell value should be 1000
condition2.FormatType = ExcelCFType.CellValue;
condition2.Operator = ExcelComparisonOperator.Equal;
condition2.FirstFormula = "1000";
worksheet.Range["A3"].Text = "Enter the Number as 1000";
// Setting fill pattern and back color to target range
condition2.FillPattern = ExcelPattern.LightUpwardDiagonal;
condition2.BackColor = ExcelKnownColors.Yellow;
// Applying conditional formatting to "A5"
condition = worksheet.Range["A5"].ConditionalFormats;
IConditionalFormat condition3 = condition.AddCondition();
// Setting conditional format rule that the cell value for target range should be less than or equal to 1000
condition3.FormatType = ExcelCFType.CellValue;
condition3.Operator = ExcelComparisonOperator.LessOrEqual;
condition3.FirstFormula = "1000";
worksheet.Range["A5"].Text = "Enter a Number which is less than or equal to 1000";
// Setting back color to target range
condition3.BackColor = ExcelKnownColors.Light_green;
// Save the Excel document
using FileStream outputStream = new FileStream("ConditionalFormat.xlsx", FileMode.Create, FileAccess.Write);
workbook.SaveAs(outputStream);