Tribicycle
I tried AmeliaBR's desaturation layer technique (www.flickr.com/groups/gimpusers/discuss/72157631670149577...) and it worked really well. I added a black layer underneath and added the "original" layer with value, then played with the curves (mostly dragged red and green down) and then did an AWB on the adjusted original layer (but should have done this after flattening the image, probably).
Tribicycle
I tried AmeliaBR's desaturation layer technique (www.flickr.com/groups/gimpusers/discuss/72157631670149577...) and it worked really well. I added a black layer underneath and added the "original" layer with value, then played with the curves (mostly dragged red and green down) and then did an AWB on the adjusted original layer (but should have done this after flattening the image, probably).