The plugin took full colour photo's, and either select colours from your palette, or randomly select an amount, and then try to match the colors as best as possible to the image.
There was a preview to the right of the window, taking up most of the plugin window, and a large white box bottom left containing the selected colours.
The result can be a pixel-esqe image or even just a monochrome image.
thanks
edit: Found, thanks to red orche
'Selective palette' here http://forums.getpai...?showtopic=8043