Free Online Color Tool
ColorExplorer is a great, easy to use colour palette tool. You can extract a palette from an image you like, add or remove colours from a custom palette. Choose a base colour and let it create palettes based on an algorithm you choose from a drop down menu (complimentary, Colormatch 5K, Triadic, etc.)
You can also do a contrast analysis, colour conversion between different systems or simply view a pickable list of swatches in from various libraries such as, W3C named, Websafe, RAL, TOYO, Focaltone, Trumatch. All of which can be sorted by hue, lightness or saturation.
