Setting Background in master slides

I am creating a powerpoint using Aspose.PowerPoint and everythings works great. However, my user wants to be able to insert new slides in the generated ppt from within MS Powerpoint and wants the background to default to the background of the other slides already in the generated ppt. How can I set the background of the MainMaster or Master slides when I am creating the ppt in Aspose.

Thanks, Jim

At first, you can use Slide.ChangeMaster function:
http://www.aspose.com/Products/Aspose.PowerPoint/Api/Aspose.PowerPoint.Slide.ChangeMaster.html

The second way is read properties of background on default Master and set the same for the new Master.