I appreciate your concern about wanting a different theme option.
While riding in the plane from Minneapolis to London and back, I read a book about branding. The product kind, not the ranch kind. One of the points that I got out of it was that brands shouldn't be dilluted by trying to be all things to all people.
This concept has direct application to the question at hand: should other "looks and feels" be permitted? I don' t think so. The bright, crisp, airy design was quite deliberate and is now an integral part of the BonnevilleClub "brand." A key component of that is black text on a light background.
This approach is not unique. As far as I know, CNN.com does not allow custom text/background colors. Neither does Slashdot. Nor FoxNews.com. In fact, I would assert that sites allowing custom foreground and background colors are the exception rather than the rule.
Does the overall desgin need freshening? Yes, but the core black-on-light-gray-with-red theme will remain.
I'm sorry about the misleading presence of the "subSilver" option. After I've slept for a while (jet lag...) I'll remove the item from the profile page. ***EDIT: Scratch that, I've changed my mind. The option is going to stay for now***
(By the way -- there are some technical reasons for not slapping in a bunch of themes, namely that they would not work with the forum mods without extensive modification)