How to apply a style *** for a single user session in SPS 2003?

I am developing a SharePoint application in C# on SPS 2003. I want the
"theme" or colors to be tied to a user session. For example, if a user in
Department A logs in, he would see a Blue theme and a logo/graphic unique to
his department, but if a user from Department B logs in, he would see a
Green theme and a logo/graphic unique to his department.

I am trying to implement all the functionality in Web Parts so I can use web
part pages and let SPS manage the storage, but I may have to development my
own ASPX pages.

I know how to identify the user and I'm going to store unique attributes in
the database on him. One thing I was considering was having an attribute
identifying which CSS file should be applied, but I don't see exactly how to
apply it. Any help would be appreciated.

Ken


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