Trying my hand at some re-colouring, I found that messing with the levels and curves before doing any hue adjustments resulted in a much richer colour. To get the multi-coloured hair I added a second hue adjustment with a layer mask to only subsections.
original:
http://images.4chan.org/e/src/1312647362319.jpgI think this took me an hour, but the result seems ok.
