Great Website for developing colour palettes. Epically from photographs or images. Really easy to use. Just create a account and it saves all your palettes which you can make available or private from the public. The only down side is that i can't seem to get a pantone reference off the website, but its easy to work around.
Just a quick example below:
The online program also gives you choices of palette tones Colourful
and Custom so you can alter a shade if your not happy with it.