You have already learnt how to add different fills for shapes in PowerPoint 2010. Just like the Pattern fill option, there is one more hidden shape fill option which you can’t access from Shape Fill gallery. The Slide Background fill option is different from other shape fill options because instead of filling something into the selected shape, it makes the slide background area behind the shape visible into the selected shape.
Learn how to add slide background fill to a selected shape in PowerPoint 2010 for Windows.

