ColorPal!

ColorPal is an HTML5 color palette generation tool.

Blog posts about ColorPal

There is also a Node.js ColorPal utility for generating color palettes from images on the command line.

Here's a recording of ColorPal itself, and then the command-line tool:

Name	Name	Last commit message	Last commit date
Latest commit mwcz clear the small canvas to ensure unpolluted results Mar 28, 2014 0a0179e · Mar 28, 2014 History 86 Commits
css	css	highlight selected swatch	Jul 22, 2013
images	images	remove old image	Mar 27, 2014
includes	includes	remove cli utility, it has moved to repo mwcz/colorpal-cli	Nov 9, 2013
js	js	clear the small canvas to ensure unpolluted results	Mar 28, 2014
median-cut.js @ 3ac583c	median-cut.js @ 3ac583c	pull newest median-cut	Jun 16, 2013
utils	utils	clean up the main directory	Jan 15, 2012
.gitmodules	.gitmodules	remove submodule	Apr 29, 2012
README.md	README.md	add note to README about cli util	Nov 9, 2013
index.html	index.html	always display color picker and color codes	Jul 22, 2013