Create Button Themes
To open Theme editor click Tools/Theme editor in the Main menu. Theme editor helps you create your own themes or modify existing ones. To select a button you would like to edit, just right-click it in the buttons on the Themes toolbox.
You can check how a background responds to the mouse events without applying it. To do so just move mouse over/click the background.
To apply chosen background, just double-click it. Selected buttons' appearance will change.
Click "Create button..." - to add new button to the current theme. After you click the "Add new" button, the "Add button" dialog will appear.