is is possible to customize movie genre options?

is is possible to customize movie genre options? At the moment there are a limited amount of options for genres in itunes. I have several more genres than are accounted for ie comedy drama as well as comedy, for which I would like to set a custom icon . I would also like to, for instance, set a genre for a specific movie star. Not giantly important in the scheme of things of course, but it would look much nicer in apple tv.

any suggestions appreciated.
thanks