Currently, pages written in mendoza have a blue background by default, and pages written in Skunk have a green background by default. I am in the process of moving all the pages to Skunk, but it takes time, especially since this is Skunk's first major outing.
If you want to see the Skunk source for a given page written in it, you can switch out the .html in the URL to .pstk, or, if it's a folder index file, add index.pstk to it.
Finally, the project file contains some StackTalk code that configures Skunk, and the style template is here.