如何在HTMLTable中为某些特定单元格着色

我为公司开发了一个培训矩阵，向所有员工展示公司提供的所有培训课程。现在，我必须以一种易于管理员编辑和更新的方式来开发它。我做了所有正确的事情，除了一件事，那就是给每组课程一个特定的颜色（因为我有三种类型的课程），从第四个单元格到最后一个单元格。仅供参考，我有两个用于开发此矩阵的SqlDataSource:

SqlDataSource1用于检索GroupID:

<asp:SqlDataSource ID="SqlDataSource1" runat="server"
                ConnectionString="<%$ ConnectionStrings:testConnectionString %>"
                SelectCommand="SELECT [ID] FROM [groups]"></asp:SqlDataSource>

SqlDataSource2将从SqlDataSource1获取GroupID，并使用它生成矩阵：

<asp:SqlDataSource ID="SqlDataSource2" runat="server"
                                            ConnectionString="<%$ ConnectionStrings:testConnectionString %>"
                                            SelectCommandType="StoredProcedure" SelectCommand="kbiReport" FilterExpression="[Division] like '{0}%'">
                            <SelectParameters>
                                <asp:Parameter  Name="GroupID"/>
                            </SelectParameters>
                            <FilterParameters>
                                <asp:ControlParameter ControlID="ddlDivision" Name="DivisionName"
                                                         PropertyName="SelectedValue" Type="String" />
                            </FilterParameters>
            </asp:SqlDataSource>

现在，由于我使用HTMLTable，我需要访问SqlDataSource1来执行一些逻辑，如：如果GroupID＝1，那么给这个组蓝色，以此类推。我可以通过以下操作来做到这一点：

我在C#中的代码隐藏：

protected void Page_Load(object sender, EventArgs e)
    {
        DataView dv2 = (DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty);
        foreach (DataRowView group in dv2)
        {
            SqlDataSource2.SelectParameters[0].DefaultValue = group[0].ToString();
            //create a new HtmlTable object
            HtmlTable table = new HtmlTable();
            DataView dv = (DataView)SqlDataSource2.Select(DataSourceSelectArguments.Empty);
            int columns = dv.Table.Columns.Count;
            int rows = dv.Count;
            //table's formating-related properties
            table.Border = 2;
            table.CellPadding = 3;
            table.CellSpacing = 3;
            table.Width = "900px";
            //to get the css style
            table.Attributes["class"] = "uGrid";
            //create a new HtmlTableRow and HtmlTableCell objects
            HtmlTableRow row;
            HtmlTableRow header = new HtmlTableRow();
            HtmlTableCell cell;

            //for adding the headers to the table
            foreach (DataColumn column in dv.Table.Columns)
            {
                HtmlTableCell headerCell = new HtmlTableCell("th");
                headerCell.InnerText = column.Caption;
                //The following if-else statements are for checking the GroupID and give each group
                //a specific color
                if (group[0].ToString().Equals("1"))
                    headerCell.BgColor = "lightBlue";
                else if (group[0].ToString().Equals("2"))
                    headerCell.BgColor = "lightYellow";
                else if (group[0].ToString().Equals("3"))
                    headerCell.BgColor = "Orange";
                //the header cells to the header
                header.Cells.Add(headerCell);
            }
            table.Rows.Add(header);
            //loop for adding rows to the table
            foreach (DataRowView datarow in dv)
            {
                row = new HtmlTableRow();
                //row.BgColor = "yellow";

                //loop for adding cells
                for (int j = 0; j < columns; j++)
                {
                    cell = new HtmlTableCell();
                    if (j < 4)
                    {
                        cell.InnerText = datarow[j].ToString();
                    }
                    else
                    {
                        CheckBox checkbox = new CheckBox();
                        int checkBoxColumns = dv.Table.Columns.Count - 5;
                        string fieldvalue = datarow[j].ToString();
                        string yes = fieldvalue.Split(new string[] { ", " }, StringSplitOptions.RemoveEmptyEntries)[1];
                        string courseid = fieldvalue.Split(new string[] { ", " }, StringSplitOptions.RemoveEmptyEntries)[0];
                        checkbox.ID = row.Cells[3].InnerText + "," + courseid.Trim();
                        checkbox.Checked = yes.Equals("Yes");
                        cell.Controls.Add(checkbox);
                    }
                    //add the cell to the current row
                    row.Cells.Add(cell);
                }
                //add the row to the table
                table.Rows.Add(row);
            }
            //add the table to the page
            PlaceHolder1.Controls.Add(table);
        }
    }

每组有不同数量的课程，但着色应从第四个单元格开始，直到最后一个单元格。我在上面代码的下面部分做了很多尝试，但都失败了，我不知道为什么那么怎么做呢

//for adding the headers to the table
            foreach (DataColumn column in dv.Table.Columns)
            {
                HtmlTableCell headerCell = new HtmlTableCell("th");
                headerCell.InnerText = column.Caption;
                //The following if-else statements are for checking the GroupID and give each group
                //a specific color
                if (group[0].ToString().Equals("1"))
                    headerCell.BgColor = "lightBlue";
                else if (group[0].ToString().Equals("2"))
                    headerCell.BgColor = "lightYellow";
                else if (group[0].ToString().Equals("3"))
                    headerCell.BgColor = "Orange";
                //the header cells to the header
                header.Cells.Add(headerCell);
            }
            table.Rows.Add(header);