Elaboration on video tutorial from Bert Monroy's Pixel Perfect: http://revision3.com/pixelperfect/labcolor
The original image (lower right) was converted into a bright green car (upper left) by inverting the red channel in LAB mode.
I restored the background colors and the flags by painting with the history brush.
With Images 2, 3, and 4, I added a layer with the original RGB color on top of the lab conversion. Changing the blending mode of the top layer produced several color variations which seem to be more realistic than the first LAB conversion.