See the demo and docs: http://bgrins.github.com/spectrum/.
I wanted a colorpicker that didn't require images, and that had an API that made sense to me as a developer who has worked with color in a number of applications. I had tried a number of existing plugins, but decided to try and make a smaller, simpler one.
I started using canvas, then switched to CSS gradients, since it turned out to be easier to manage, and provided better cross browser support.
Spectrum is registered as a jQuery plugin on the jQuery plugin repository here: http://plugins.jquery.com/spectrum/
Thanks to the following places for good information as this plugin was being built:
- http://ansciath.tumblr.com/post/7347495869/css-aspect-ratio: Aspect ratio using CSS only
- https://github.com/DavidDurman/FlexiColorPicker for saturation/value gradient constants
- http://upload.wikimedia.org/wikipedia/commons/a/ad/HueScale.svg: For hue gradient contants
