Hi there,
that would take some custom coding and i am not sure what Tom has planned in this area just yet.
currently this would require some CSS to be added to the page, which can be done with Tom’s Simple CSS plugin as it adds a page specific Simple CSS meta box to the page editor.
The other method if you can identify the pages by Page ID or template type we can target a body class.
Or with the new GP 1.7 (beta) Elements module we could use a hook to enqueue the different CSS and then apply it using the Display Rules.
Let me know