Im not sure Im posting in the right area, but here goes,

Iv come across a really good website thats used excellent css or I think good use of html pages to program a site to have a different coloured theme each time you click onto the company logo, or just generally click on to the homepage.
When you click on the logo it changes to i.e blue, green , etc and a few other elements on the page and a number of pictures on the top right hand corner.

However I have been trying to suss out the code but how can you have mulitple home pages (you can only save one document to home.htm)
that contain the <link rel="stylesheet" type="text/css" href="17.css" media="screen" /> where the different themes are.

I dont get it.

i would like to post the link but Im not sure if i can as it belongs to a web design agency but Im just exploring and looking at different types of cool websites to build as I want to build one for my own business.

any help or suggestions ?