Hi there!
thanks for your feedback and your comments.
I think the first feature you suggest (filtering by keyword) it’s already built in. In the calendar settings you have a search keywords input. If you add Keywords here, you will filter events. And works with negative keywords too or ‘OR’ conditions
You can try using these common search operators: https://support.google.com/websearch/answer/2466433?hl=en (except probably those specific to websites).
You can try with: “-rental -staff” (without quotes) if you want to exclude these terms.
However, adding these to a shortcode is not so simple. Because of caching it’s unlikely you will have reliable results even if this was implemented. The calendar is queried from Google before the shortcode parses its attributes – which normally alter the appearance of the calendar and other things.
Alternatively though, you might create different calendars, with different keywords settings and embed those into your posts.
As for your second idea.
Google has already the ability to color-code events. But the current api key system doesn’t seem to allow to import this setting. Me and others have plans to make a different ‘client’ for Google which uses Oauth which would allow us to make more things, including using private calendars.
Color coding from Google would be the way to go as WordPress has no idea what those events are or to which category they belong.
However, it’s also in the roadmap to improve styling possibilities for the calendars (ok, not specifically events) using the WordPress customizer. In this way people wouldn’t have to touch CSS (although they still could if they want).
I hope you can work something out with the search query field. Sorry if this is not what you were looking for. Buy you can suggest more features. Also link your site so we can see how you are using the plugin, that would be helpful too.
Thank you