C# 背景单元格取决于条件

我有用c#为excel单元格的背景着色的代码，如：

现在，正如您在下一张图片中所看到的，值正确地更改为“Retrasado”，但列bakgrond获得了一个额外的规则，它绘制一个和下一个no，依此类推，而不是绘制所有具有“Retrasado”值的人

 xlAppToExport = new Application();
 xlAppToExport.Workbooks.Add("");
 xlWorkSheetToExport = (Worksheet)xlAppToExport.Sheets[1];

  if (Int32.Parse(task.progress) < 100 && currentDate > task.duedate)
                    {
                        xlWorkSheetToExport.Range["F2", "F5000"].Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);
                    }
                    else
                    {
                        xlWorkSheetToExport.Cells[2, 6] = task.StatusDescripcion;
                    }

xlAppToExport = new Application();
 xlAppToExport.Workbooks.Add("");
 xlWorkSheetToExport = (Worksheet)xlAppToExport.Sheets[1];

  if (Int32.Parse(task.progress) < 100 && currentDate > task.duedate)
                    {

xlWorkSheetToExport.Cells[fila, 6].Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Red);

      /* I added this to identified what columns get validation, 
     so all columns who have value "Retrasado" equals to validation is true*/
        xlWorkSheetToExport.Cells[fila, 6] = "Retrasado";
                    }
                    else
                    {
                        xlWorkSheetToExport.Cells[2, 6] = task.StatusDescripcion;
                    }