Some design elements (borders, backgrounds, icons…) are placed inside the master slides. If you want to change these elements on all slides of your presentation, you can edit the master slide.
1. To do so, open the Slide menu, then select Edit master.
2. The presentation will switch to the master template editor and you’ll see all the layouts available in the left pane.
3. Now, make the desired changes to the master slide. For example, you can change the text font, color or move elements.
4. When you’re finished, close the master template editor by clicking the X at the top right of the pane.
The changes will apply to all slides in the presentation.