How to change an Excel cell's background color?

'oSheet' is intended to be the variable name for your Excel._Worksheet object.

I was expecting that you'd already have a lot of Excel interop code written and were just wanting to slot this piece of code into that. However, it sounds like that's not the case :)

As Excel interop is a complicated subject, I'd read this Microsoft article before you do anything else :

http://support.microsoft.com/kb/302084

You will need to add a reference to whatever is the latest Excel object library on your machine and will also need this using directive in your C# source code file to get it all to work:

using Excel = Microsoft.Office.Interop.Excel;