EXCEL Interior in C#, VB.NET

		private void ExcelDocViewer( string fileName )
		{
			try
			{
				System.Diagnostics.Process.Start(fileName);
			}
			catch{}
		}

		private void btnRun_Click(object sender, System.EventArgs e)
		{
			Workbook workbook = new Workbook();
			Worksheet sheet = workbook.Worksheets[0];
			workbook.Version = ExcelVersion.Version2007;


			int maxColor = Enum.GetValues(typeof(ExcelColors)).Length;
			Random random = new Random((int)System.DateTime.Now.Ticks);
			for (int i = 2; i < 40; i++)
			{
                
			ExcelColors backKnownColor = (ExcelColors)(random.Next(1,maxColor / 2));

			sheet.Range["A1"].Text = "Color Name";
			sheet.Range["B1"].Text = "Red";
			sheet.Range["C1"].Text = "Green";
			sheet.Range["D1"].Text = "Blue";
			sheet.Range["E1:K1"].Merge();
			sheet.Range["E1:K1"].Text = "Gradient";
			sheet.Range["A1:K1"].Style.Font.IsBold = true;
			sheet.Range["A1:K1"].Style.Font.Size = 11;

			string colorName = backKnownColor.ToString();
			sheet.Range[string.Format("A{0}",i)].Text = colorName;
			sheet.Range[string.Format("B{0}", i)].Text = workbook.GetPaletteColor(backKnownColor).R.ToString();
			sheet.Range[string.Format("C{0}", i)].Text = workbook.GetPaletteColor(backKnownColor).G.ToString();
			sheet.Range[string.Format("D{0}", i)].Text = workbook.GetPaletteColor(backKnownColor).B.ToString();

			sheet.Range[string.Format("E{0}:K{0}",i)].Merge();
			sheet.Range[string.Format("E{0}:K{0}", i)].Text = colorName;
			sheet.Range[string.Format("E{0}:K{0}", i)].Style.Interior.FillPattern = ExcelPatternType.Gradient;
			sheet.Range[string.Format("E{0}:K{0}", i)].Style.Interior.Gradient.BackKnownColor = backKnownColor;
			sheet.Range[string.Format("E{0}:K{0}", i)].Style.Interior.Gradient.ForeKnownColor = ExcelColors.White;
			sheet.Range[string.Format("E{0}:K{0}", i)].Style.Interior.Gradient.GradientStyle = GradientStyleType.Vertical;
			sheet.Range[string.Format("E{0}:K{0}", i)].Style.Interior.Gradient.GradientVariant = GradientVariantsType.ShadingVariants1;
			}

			sheet.AutoFitColumn(1);
		
			workbook.SaveToFile("Sample.xlsx");

			ExcelDocViewer(workbook.FileName);
		}

		Private Sub ExcelDocViewer(ByVal fileName As String)
			Try
				System.Diagnostics.Process.Start(fileName)
			Catch
			End Try
		End Sub

		Private Sub btnRun_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnRun.Click
			Dim workbook As New Workbook()
			Dim sheet As Worksheet = workbook.Worksheets(0)

			workbook.Version = ExcelVersion.Version2007


			Dim maxColor As Integer = System.Enum.GetValues(GetType(ExcelColors)).Length
            Dim random As New Random()
			For i As Integer = 2 To 39

				Dim backKnownColor As ExcelColors = CType(random.Next(1,maxColor \ 2), ExcelColors)

				sheet.Range("A1").Text = "Color Name"
				sheet.Range("B1").Text = "Red"
				sheet.Range("C1").Text = "Green"
				sheet.Range("D1").Text = "Blue"
				sheet.Range("E1:K1").Merge()
				sheet.Range("E1:K1").Text = "Gradient"
				sheet.Range("A1:K1").Style.Font.IsBold = True
				sheet.Range("A1:K1").Style.Font.Size = 11

				Dim colorName As String = backKnownColor.ToString()
				sheet.Range(String.Format("A{0}",i)).Text = colorName
				sheet.Range(String.Format("B{0}", i)).Text = workbook.GetPaletteColor(backKnownColor).R.ToString()
				sheet.Range(String.Format("C{0}", i)).Text = workbook.GetPaletteColor(backKnownColor).G.ToString()
				sheet.Range(String.Format("D{0}", i)).Text = workbook.GetPaletteColor(backKnownColor).B.ToString()

				sheet.Range(String.Format("E{0}:K{0}",i)).Merge()
				sheet.Range(String.Format("E{0}:K{0}", i)).Text = colorName
				sheet.Range(String.Format("E{0}:K{0}", i)).Style.Interior.FillPattern = ExcelPatternType.Gradient
				sheet.Range(String.Format("E{0}:K{0}", i)).Style.Interior.Gradient.BackKnownColor = backKnownColor
				sheet.Range(String.Format("E{0}:K{0}", i)).Style.Interior.Gradient.ForeKnownColor = ExcelColors.White
				sheet.Range(String.Format("E{0}:K{0}", i)).Style.Interior.Gradient.GradientStyle = GradientStyleType.Vertical
				sheet.Range(String.Format("E{0}:K{0}", i)).Style.Interior.Gradient.GradientVariant = GradientVariantsType.ShadingVariants1
			Next i

			sheet.AutoFitColumn(1)

			workbook.SaveToFile("Sample.xlsx")

			ExcelDocViewer(workbook.FileName)
		End Sub