Choose File▶New▶Presenter Notebook... and choose theme, font and color options to customize its appearance. Click Create to create a presenter notebook with the selected options:
You can reuse customized themes for brand new presenter notebooks with the Import button.
While Editing an Existing Presentation...
Choose Theme Options from the More... menu () on the right of a presenter notebook toolbar to open the Theme Options dialog. Choose theme, font and color options, then click Apply to apply the styles to the presenter notebook: