PowerPoint 2010 lets users to choose different themes for the slides from the Design menu. Users can also customize the themes by changing the Fonts, Colors, Background Styles and adding effects to the slides. We have already seen about the steps required top copy the existing theme to new presentation but if you want to save this theme and apply this for your future PowerPoint files then you can use the Save theme feature available in PowerPoint 2010.
After customizing the theme, navigate to Design menu and select More option.
This would display the following All Themes drop down with the Save Current Theme option available at the bottom of the window.
Clicking the Save Current Theme, should display the save dialog as shown below.
Provide a name for the theme and click the Save button. The customized theme will now be available under the Custom theme section.