Have you tried to change the theme for just one slide in your PowerPoint 2008 presentation? Are you frustrated because there is no "Apply to Selected Slides" option like there is PowerPoint's Windows counterparts? You are not alone. I struggled with this for what seemed like forever until I discovered the easy, albeit completely hidden, solution.
- In PowerPoint 2008, right-click (or [Command]-click if you do not have a right-clicker) a slide and choose Duplicate Slide.
- Hold down the [Shift] key and select both the original slide and its duplicate.
- Right-click (or [Command]-click if you do not have a right-clicker) either slide, and choose Slide Theme > From Gallery.
- You can now select a new Slide Theme from the gallery and delete the duplicate slide.