Google Slides allows you access to the slide master view using the menu options. Here’s what you need to do to access the slide master in Google Slides.
Click on the “View” menu. Now, all you have to do is click on the “Theme Builder” option from the dropdown menu under the “View” button.
As soon as you click on the “Theme Builder”, you will be able to access the slide layouts in the slide master in Google Slides.
In the slide master view, you can edit the theme, the contents, and the layouts for all the slides in the particular Google Slides presentation.
To edit the existing placeholder, click on the text level you want to edit. Then you can change the “Font”, “Font size”, “Text color”, “Alignment”, etc. from the toolbar.
To edit the background of the master slide, all you have to do is click on the “Background” button on the toolbar. Then you can select the “Background color” or the “Background image”.