The definition of a page style is based on two distinct objects: "master page" and "page layout". A "master page" object encompasses any page style content (i.e. the content of headers and footers) and links to a "page layout" object which describes page presentation characteristics (with a lot of properties from page dimensions to background colour to footnote separator size, etc). The names which appear in the list of page styles in OpenOffice.org are actually names of "master pages".
The appropriate methods to create and/or update a page styles (master page and layout), are createMasterPage(), createPageLayout(), updatePageLayout(), masterPageExtension(), ..., and all the methods whose name contains "page". They are described in the
OpenOffice::OODoc::Styles manual chapter.