dynamically rows colour changing into using excel.range in C#

i want to row color changing one by one using for loop in my Export Excel File my code following :


Microsoft.Office.Interop.Excel.Application excelApplication = new Microsoft.Office.Interop.Excel.Application();


Microsoft.Office.Interop.Excel.Workbook workbook = excelApplication.Workbooks.Open(filename,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);






foreach (Excel.Worksheet wrkst1 in workbook.Worksheets)
{

Excel.Range usedrange = wrkst1.UsedRange;
usedrange.Columns.AutoFit();
wrkst1.Tab.Color = 279;



//Excel.Range formatRange;
//formatRange = wrkst1.get_Range("b1", "k6");
//formatRange.Interior.Color = System.Drawing.
//ColorTranslator.ToOle(System.Drawing.Color.YellowGreen);


//formatRange = wrkst1.get_Range("b7", "k20");
//formatRange.Interior.Color = System.Drawing.
//ColorTranslator.ToOle(System.Drawing.Color.Yellow);

Excel.Range rng = (Excel.Range)wrkst1.Cells[1, 1];
Excel.Range row = rng.EntireRow;
row.Insert(Excel.XlInsertShiftDirection.xlShiftDown, false);

//wrkst1.get_Range("E1", "F1").Merge(false);
Excel.Range chartRange;
chartRange = wrkst1.get_Range("E1");
chartRange.FormulaR1C1 = objModule.Title;
chartRange.HorizontalAlignment = 3;
chartRange.VerticalAlignment = 3;
//chartRange.Interior.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Yellow);
chartRange.Font.Color = System.Drawing.ColorTranslator.ToOle(System.Drawing.Color.Green);
chartRange.Font.Size = 20;

//ColorConverter cc = new ColorConverter();
//wrkst1.Cells[1, 10].Interior.Color = ColorTranslator.ToOle((Color)cc.ConvertFromString("#F1DCDB"));


}


excelApplication.DisplayAlerts = false;
((Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1]).Delete();
workbook.Close(true, filename, null);
excelApplication.DisplayAlerts = true;


}

catch (Exception ex)
{
}


//return File(filename, "application/msexcel");
return File(filename, "application/x-excel", DateTime.Now.Ticks + "_Report.xlsx");
}