How to delete a property?

[Petit Suisse]

Noob here and just had my first experience with Alice today. Made a simple animation with a bunny moving from one side of the screen to the center, then speaking.

I played around with the properties and changed the text bubble color, etc, however in the end I wanted the colors to be default and had to manually set the various properties to no color. This shows up when you print the project, however I would rather the properties I don't want to customize not show up there.

How do you delete those?

Thanks for any useful tips.