It is possible to make changes to all slides within a presentation, like changing the text size of all slide titles. If in doubt, Microsoft has identified several templates that are optimized for accessibility. While this doesn't guarantee accessibility, it increases the likelihood of finding a good template. Add the word 'accessible' to the search for templates that are tagged as 'accessible' by the creator. You can search for a template by selecting File > New, and then describing the template in the Search field.
In addition to built-in and custom themes, there are thousands of templates available for download. If the presentation will be viewed on a projector, the contrast and readability may need to be even more pronounced. Be sure to choose a theme with good contrast and with simple backgrounds. Some of these templates have low contrast between slide text and the slide background, and a few may also have busy backgrounds that can make text even more difficult to read. The Design tab contains many built-in Themes and color Variants that can be used to change the look of a presentation, as well as the ability to create custom themes The first step in creating a PowerPoint presentation is choosing a slide theme or template.
