K2 templating has no limits
K2 has its own default css file loaded for categories and items.
In K2, it's possible to define new templates and affect them to a category but the css style file is still the same.
With this plugin, you can add a specific css file to a category having a specific template.
Many options to fit your needs
Keep/remove K2 core css
Works perfectly with the 'K2 Template Manager' extension
This extension is now available in 2 versions :
1.2.7 : For Joomla! 1.5, K2 2.5.x
1.8.1: For Joomla! 2.5/3.0, K2 2.5.x/2.6.x
This is a must have plugin, if you want to run multiple K2 templates or use advanced CSS based styling changes to K2 templates.