[07d046]

Interesting idea, but I think there's a variable you're missing, which is the light by which the physical object is illuminated by. The colour temperature and spectral power distribution of the light makes a difference. If you used a custom white balance in your camera you should be able to get the colour temperature close to right (depending on how neutral the camera is), but to calibrate colours you'll need a high quality light source (real daylight is quite good, but varies a lot). At this point, a cheap calibrator is probably easier and far more accurate.