Some changes do not require approval for "Publication," and are not recorded in the Version History. They must therefore be un-done or re-created by hand, if necessary. In particular, at the present time those changes include the following:
Page Background Color.
Page Primary Table Width -- from layout properties on the page, or with some base templates, from the render options.
Image layout and header location changes (adding a header is a change that is subject to being submitted for publication).
Element inheritance security restrictions in a template.