Форуми / Cotonti / Skins / Colour Schemes

Themes can have different colour schemes, but how exactly does this work?

I did a search on the website here but didn't find much information on the subject.

Can someone point me in the right direction or answer the question here?

Thanks.

Oh btw - since skins are called themes nowadays with Siena, maybe it's better to change the forum category name. :)