Firstly i changed color borders of my sheet to white, because i want to have a white sheet. Then i made some headers and want to make border around it. The Problem is it made borders between the values in header but top, down are not seenable.

My code:

           xlWorkSheet5.Columns.Borders.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.White); // Color Sheet5 to white, BusLoad
            xlWorkSheet5.Columns.NumberFormat = "@";
            Excel.Range rng = (Excel.Range)xlWorkSheet5.get_Range("A7","J7");
            rng.RowHeight = 25.5;
            rng.BorderAround2(Excel.XlLineStyle.xlContinuous, Excel.XlBorderWeight.xlHairline, Excel.XlColorIndex.xlColorIndexAutomatic, Excel.XlColorIndex.xlColorIndexAutomatic);
            rng.Borders.LineStyle = Excel.XlLineStyle.xlContinuous;
            rng.Borders.Weight = 1d;
            rng.Font.Bold = true;
            rng.HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignCenter;
            rng.Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.LightGray);