The steps depend on your user interface mode.
User Interface Mode
Ribbon or Reflection Browser
With a session open in Reflection, from the Quick Access Toolbar, click .
On the Reflection menu, tap the gear icon and then select Document Settings.
To create a theme file
Select this option to show the theme files distributed with Reflection.
Select this option to show the theme files that you've previously modified and saved. If the file you want doesn't appear in the list, click Browse to select it.
Note: The file must be in a trusted location.
Use the new file in the current session document
Use the file you are about to create with the current session.