You could try this forum
(you may need to log in again after clicking on the link) at the Cafe Home. There are some out-and-out Excel gurus there, believe me.
If you're just looking to make it look better
, though, Excel Tip
has plenty of info, and of course the home page for Excel
at Microsoft.com is an excellent resource, although it's like reading medical journals.
What you're asking is actually kind of difficult, since it's hard to say what exactly you're looking for. What I think is a "cool" or "useful" color scheme is probably not going to work for you because tastes differ so much. Probably you're just going to need to experiment with it and find something you like, or at least, something you can live with.