This is very nicely done, but I still prefer the simplicity of <http://davidbau.com/colors/>. Despite being only 2-dimentional, I find that layout strangely more intuitive. I think the author manually tweaked the color positions, so that may be the reason.
What do you mean? It's just a static HTML table and it looks fine on both my Android 11 phone with Opera and in Firefox's Responsive mode on the desktop. It may not be mobile-friendly, but that's not inherently bad, especially for something that's not meant to be used on a phone.
