This was at the top of Reddit and HN the other day. I just figured I’d share.
https://tallys.github.io/color-theory/
It’s a neat little app/article that explains color theory really well, using Sass code as examples. If you click the Ok -> Why? button on the right of each section, then you can read well written explanations of why she does each thing.
(I also wanted to try the reddit-like link posting feature of Discourse that didn’t seem to work out too well)