Well, I have checked your code a bit, it seams fine to me. Related setting colors i just want you to set headers color with standard colors in the template file using MS Excel (Opening the template file in MS Excel). Actually I want you to do this for color lost issue.
I have attached a test project which works fine here, The zip file which contains .asp file, Northwind1.mdb and a template excel file. I extract some fields from Employees table and process the smart markers to fill data into the sheet. Please check the template file for specifying how to place multivalued variables markers first and explore the code and then make your own solution (template file + code (.asp file)) based on this test project.
For deployment, you need to put .asp and Northwind1.mdb files into.....Inetpub\wwwrooot\ folder. Open the brower and write url: http://localhost/filldata.asp. And also put the template file mbook1.xls into ....d:\test\ folder or change into the .asp file code.