Which action changes the background color to black background 1 lighter 35%?

The action that successfully changes the background color to "black background 1 lighter 35%" involves using the background button's arrow and selecting the specific color option that corresponds to that description. This choice is accurate as it implies accessing a predefined color palette designed for background customization, which includes various shades that are variations of black.

In particular, "black background 1 lighter 35%" is a specific shade available within the theme colors of PowerPoint. This choice signifies a standard method of changing the background through the theme's color selections, allowing for precise adjustments to the background's appearance in line with the overall design of the presentation.

Utilizing this method enables users to maintain design consistency and ensures that the chosen color complements the text and other elements on the slides.