For people who are curious about theming here is classic GitHub done entirely in Semantic UI. http://semantic-org.github.io/example-github/

(Click the small paint icon in the top menu to swap themes to see in native SUI)

I did a meteor dev night where I talked about some of the ideas behind Semantic UI, which might clear up some of the linguistic origins for the library and it's ideas about language: https://www.youtube.com/watch?v=86PbLfUyFtA

And if anyone wants to dig really deep, there are a few podcasts as well https://changelog.com/podcast/106 https://changelog.com/podcast/164