From the “View” or “Slide Master” tab, click Themes, and choose ‘Save Current Theme’. The Save Current Theme dialog box opens. If needed, navigate to C:\\Users\\username\\AppData\\Roaming \\Microsoft\\ Templates\\Document Themes. (That location may appear automatically). Right-click the theme file and choose ‘Rename’. Type the new name of theme and press Enter.

From the “View” or “Slide Master” tab, click Themes, and choose ‘Save Current Theme’. The Save Current Theme dialog box opens. If needed, navigate to C:\\Users\\username\\AppData\\Roaming \\Microsoft\\ Templates\\Document Themes. (That location may appear automatically). Right-click the theme file and choose ‘Rename’. Type the new name of theme and press Enter.