Use the Slide Master to Apply Universal Changes
The secret to achieving consistency in customized elements across long presentations is proper usage of the PowerPoint Slide Master. A Slide Master acts as the foundation for the presentation – it contains the visual and typographic elements on which the presentation is built.
The Slide Master enables you to make universal style changes to a presentation. Without this useful feature, you’d be forced to make changes on individual slides and lose consistency, resulting in shoddy work.
To access the Slide Master, go to View>Masters>Slide Master.