How to change the original theme using Theme Designer for solutions created from template

If you create a solution from template with themes created by Theme Designer you may face the challenge of editing it with Theme Designer Add-in.

To save changes of existing theme for this case, please follow the next steps:

1. Open Theme Designer and change needed theme
2. Save theme as new with a new name
   
3. Apply the new theme to the current page or master page (as original theme)
   
4. Than choose original theme, click on 'Apply Theme' on the ribbon again and Unapply original theme
   
5. Refresh the page and check if changes applied. If everything works as expected you can delete original theme and rename the new theme on Add-in home page