Ah I see – I misunderstood first time round. So one technique would be to add a snippet like this one to your theme’s functions.php file – the advantage being, you can have a single snippet responsible for adding event categories to all the different places you want to add them to – and that would make it easier to maintain/update in the future.
Alternatively you could override and customize individual templates (in the case of list view for example you might do so with list/single-event.php).
I hope that helps – and do check out our Themer’s Guide (link over in the right under Useful Resources) if you are unfamiliar with the customization process.
Thanks!