A D3 color picker component. It's a color picker...and a slippy map.
Based on Eric Fischer's perceptually accurate color spectrum, using Tom MacWright's JavaScript implementation.
d3.select('body')
.append('div')
.call(ColorPicker()
.width(700)
.height(500)
.on('mouseup', function(c) { console.log(c) }));
// or whatever you want to do with the hex color returned on click