Elegant and well-executed, but, and this is probably just my lack of imagination as someone who is not colour blind, I'm having trouble coming up with uses cases, and most of the examples on the site aren't really convincing to me.

Usually when we try to communicate something with colour, it's not the colour itself that matters, but the colour being distinguishable and/or the associations we have with it, which someone who is colour blind may not even have. Like, if you have a big, red emergency stop button, it being red isn't really what matters; it's red because it stands out and because we associate it with danger. Adding a dot isn't going to help with that, so to make it accessible to colour blind people, it needs additional features to make it stand out and instantly convey its purpose.

That said, I did bookmark the site, in case something comes up where it's the colour itself that's important.