Sure, it's an input type="color" with some css applied to it. On webkit, it becomes a picker, on other browsers, just a text input. When it is changed, we loo

Sure, it's an input type="color" with some css applied to it. On webkit, it becomes a picker, on other browsers, just a text input. When it is changed, we loop through various elements and change their background color. The way the themes are generated is a little more complicated, but I don't think that's what you're asking about.