Where is SVsFontAndColorStorage2 defined/documented?

I am working on managed a Visual Studio 2012 add-in, and need to perform a IVsFontAndColorStorage2.RevertAllItemsToDefault().  To do this, I need to obtain anIVsFontAndColorStorage2 interface.  And to do that, I need call GetService with and argument ofSVsFontAndColorStorage2. 

I'm having trouble finding any documentation on SVsFontAndColorStorage2.  On the page http://msdn.microsoft.com/en-us/library/microsoft.visualstudio.shell.interop.ivsfontandcolorstorage2(v=vs.110).aspx that documents IVsFontAndColorStorage2, it mentions SVsFontAndColorStorage2, but doesn't have a link to its documentation. Searches for SVsFontAndColorStorage2 haven't turned up anything either.  I have Microsoft.VisualStudio.Shell.Interop and Microsoft.VisualStudio.Shell referenced, but it doesn't seem to be in either of those namespaces.

Where is SVsFontAndColorStorage2 defined, and where it is documented? 

Thanks.