A feature I like is that every color you create is kept on the palette so you can build new colors upon previous ones. It's also kind of a natural way to create a history of the colors you used. Colors that are removed from the palette are kept on the side so you can temporarily reduce the complexity of the palette.
For the technical side, it is made with regular js/html/css and webgl, no framework is required. It is supposed to work on touch devices as well as desktop computers.
This is still a bit experimental so I'd be very happy to have some feedback. Thank you!