title: label backbround color not working properly when export to excel in asp.net
body: <p>can any one help me to solve the issue 
  i am giving background color to label dynamically  but it is not showing in excel sheet when i am exporting to excel
  her is my code</p>
  
  <pre><code>DataSet ds = DST;
  ds.Tables.Remove(ds.Tables[0]);
  
  // string style = @"&lt;style&gt; .text { mso-number-format:\@Medium Date; } &lt;/style&gt; ";
  
  lblTitle.Text = "&lt;h3 border='0' align='center'&gt;&lt;b&gt;Sales Report &lt;/b&gt;&lt;/h3&gt;";
  HtmlForm form = new HtmlForm();
  string attachment = "attachment; filename=BPOSalesReport.xls";
  Response.ClearContent();
  Response.AddHeader("content-disposition", attachment);
  Response.ContentType = "application/ms-excel";
  
  StringWriter stw = new StringWriter();
  HtmlTextWriter htextw = new HtmlTextWriter(stw);
  GridView gv;
  Panel PNl = new Panel();
  Label lbldate;
  LiteralControl ltlbldate;
  
  for (int k = 0; k &lt; ds.Tables.Count; k++)
  {
      gv = new GridView();
      lbldate = new Label();
      ltlbldate = new LiteralControl();
      //lbldate.CssClass = "required";
      gv.ID = ds.Tables[k].TableName;
      gv.DataSource = ds.Tables[k];
      gv.DataBind();
      gv.HeaderRow.Style.Add("background-color", "#6699FF");
      gv.HeaderStyle.ForeColor = System.Drawing.Color.Black;     
  
      lbldate.Text = datechecking(ds.Tables[k].TableName.ToString());
      lbldate.BackColor = System.Drawing.Color.Yellow;
      PNl.Controls.Add(lbldate);
      PNl.Controls.Add(gv);
      PNl.Controls.Add(new LiteralControl("&lt;br /&gt;"));
      PNl.Controls.Add(new LiteralControl("&lt;br /&gt;"));
      PNl.Controls.Add(new LiteralControl("&lt;br /&gt;"));
  }       
  
  form.Attributes["runat"] = "server";
  form.Controls.Add(PNl);
  this.Controls.Add(form);
  lblTitle.Visible = true;
  lblTitle.RenderControl(htextw);
  form.RenderControl(htextw);
  // Response.Write(style);
  
  Response.Write(stw.ToString());
  Response.End();
  </code></pre>