Just uploaded a new version of ShadowBox to wordpress.org. This new version contains many of the innovations I developed for Translucence including opacity settings for most layout areas of the blog. As well, I’ve improved the theme options model so that it is much more what-you-see-is-what-you-get (WYSIWYG). See:
http://wordpress.org/extend/themes/shadowbox
Hope to release Translucence soon.