Tom Bennett suggested desaturating the green color before painting on a color layer.
This procedure had widely varying effect depending upon the underlying colors.
I desatuurated the face green, plus 3 other areas in the image, then painted with a skin color over all 4 areas.
Notice the changes in the appearance, as well as the color information as the desaturated layer is turned off and on.
There is actually very little effect on the skin and orange background, but a larger change on the green background and the blue t-shirt.


forum discussion: http://forums.dpreview.com/forums/read.asp?forum=1006&message=26154285