ASP.NET

protected  void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{

Label myLabel = (Label)e.Row.FindControl("yourlabel");

if (myLabel.Text == "Jack")
{
    'change the colour here
}

}

for (int i = 0; i < gvPpl.Rows.Count; i++)
           {
               Label lblL = (Label)gvPpl.Rows[i].Cells[2].FindControl("lblFirstName");
           }

void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{    
    if (e.Row.RowType == DataControlRowType.DataRow)    
    {           
         Label lblFirstName= (Label)e.Item.FindControl("lblFirstName");       
         if(lblFirstName.Text == "John")             
            lblFirstName.ForeColor=Color.Red;      
         else if(lblFirstName.Text == "Jim")
            lblFirstName.ForeColor= Color.Blue;
    }
}

<div style="padding-left: 10px; padding-right: 10px; text-align: left; width:45%">
                                             <asp:Label ID="lblFirstName" runat="server" Text='<%#Server.HtmlEncode(Eval("FirstName").ToString())%>'></asp:Label>
                                            </div>

protected void gvPpl_DataBound(object sender, GridViewRowEventArgs e)
       {


           for (int i = 0; i < gvPpl.Rows.Count; i++)
           {
               Label lblL = (Label)gvPpl.Rows[i].Cells[2].FindControl("lblFirstName");
               Label lblL1 = (Label)gvPpl.Rows[i].Cells[1].FindControl("lblFirstName");
               Label lblL2 = (Label)gvPpl.Rows[i].Cells[0].FindControl("lblFirstName");
               Label lblL3 = (Label)gvPpl.Rows[i].Cells[3].FindControl("lblFirstName");
           }
       }

myGridview.Sort("Column1", SortDirection.Descending);

private SortDirection GridViewSortDirection
{
   get
   {
      if (ViewState["sortDirection"] == null)
          ViewState["sortDirection"] = SortDirection.Ascending;
      return (SortDirection)ViewState["sortDirection"];
   }
   set 
   { 
      ViewState["sortDirection"] = value; 
   }
}

protected void btnClick(object sender, EventArgs e)
{
   ViewState["SortExpression"] = sortExpression;
   if (GridViewSortDirection == SortDirection.Ascending)
   {
      GridViewSortDirection = SortDirection.Descending;
      SortGridView(sortExpression, DESCENDING);
   }
   else
   {
      GridViewSortDirection = SortDirection.Ascending;
      SortGridView(sortExpression, ASCENDING);
   } 
}

private void SortGridView(string sortExpression, string direction)
{
  DataView dv = new DataView(dt);
  dv.Sort = sortExpression + direction;
  gvHours.DataSource = dv;
  gvHours.DataBind();
}