Based on the new Ribbon navigation of PowerPoint 2007, the Set Color Transparent tool is a little harder to find than it was in PowerPoint 2003. If you’re using PowerPoint 2007, left-click on the photo image that you want to edit. Then on the far-right of the top Ribbon, select Picture Tools > Format . On the far-left of the Ribbon under the Adjust section, click on the Recolor button . At the very bottom of the subsequent menu that appears, click on the Set Color Transparent button . The pointer will then change its appearance, and you just need to click a solid color within the picture to make it transparent. If you’re using PowerPoint 2003 , you can find this feature on the main menu in this manner ( View > Toolbars > Picture ).