Trouble removing subscribed calender events.

I'd like to remove calendar events, more specifically holiday events which I've subscribed to.  I have added certain country's holidays to my calendar but would now like to clean it up. How do I delete the holidays I no longer wish to see?

Also how do I manage the colour settings which I've selected and named to use for events I enter. I don't want so many colours and would like to delete the unwanted labels?

I hope there is a way to clean up this calendar without having to start all over again with a new one.

Thanks for any feedback.