I'm trying to put together a geeky blog where the user can, ideally without even logging in, change the color scheme, the banner image and the category icons fitting different styles. I'm looking for suggestions on plugins and themes for what I'm trying to do, and any help would be much appreciated.
For instance, a user could choose between a medieval fantasy style, which would have the the banner have the logo surrounded by a magical forest and icons could be such things as swords and spellbooks with a faint castle background, or a sci-fi style with the banner being a space station orbiting an alien planet and icons being starships and ray guns with a faint nebula background. The colors schemes (font, background, link text, etc) would also be changed depending on the chosen style.
The setup I'm looking for includes small text links at the very top right-hand side of the page and at the very bottom of the page to static pages (about page, contact form, etc). Then a wide header banner with text over an image, and a menu of all the categories directly below that with small category icons and text titles that link to the pages that only display posts of the selected category. Below that would be the posts with small category icons, ideally each icon linked to the above category page. At the top and bottom of the page would also be a button that triggers a drop-down menu with style options, where upon selection the site refreshes to apply the chosen style.
This is an ideal, and I realize I may have to compromise (such as the color scheme not being changed, or only being able to change the category images and not the banner image, or requiring the user to have to log in to make the changes). But I'd appreciate anyone with more experience customizing WordPress who could chime in with suggestions!