Set Style
It's used to edit the appearance of each component.
Usage
Mostly used to appearance a component once it created. Therefore, we can drag Set Style after clicking "created" of the selected component, then click a gear on the side of Set Style to edit the properties.
Hands on:
Simply drag as following example to edit the button appearance. Or otherwise, you can also drag another Set Style into pressed event of Button to make changes to button appearance when user pressed the button.