version 3. Create path/vectors of color fills as well.
(4.44 KiB) Downloaded 210 times
Plug-in Menu Location: Python-fu/Simplify...
Have your image opened (rgb mode).
Run plug-in (Python-fu/Simplify...), Choose number of colors (to reduce to using indexed mode). Choose simply size width (pixels) (It'll use this width to scale image down, turn to paths and resize to normal size, this is what simplifies the image, the smaller the width the more detail you'll lose, so far I have only tested 100 to 200 sizes).
Then click OK to run plug-in.
That's it, when it's done you can change the bottom-most layer to a solid color, or blur it with a large radius (this layer contains your indexed colored of original image).