abc1234 wrote:
Even if you were there, you would have to remember the shade and that would be quite a trick. Do our eyes have something like the perfect pitch that ears have? Or can you hold up the top to the monitor and adjust from there? The skin looks a little warmer. If you want a bluer blue or as the old commercial bragged, a whiter white, then adjust the specific luminance and saturation.
But as a practical matter, how many viewers would even be aware of this issue?
Not many, to be honest. The main purpose is to maintain consistency between shots taken under various lighting conditions (not purely down to white balance) and between one or more camera bodies (of whichever manufacturer, and their color response really does vary quite a lot). This can then be achieved globally, without having to adjust every single shot individually for saturation and color balance. i.e. by generating a camera profile (much like a monitor or printer profile) for ACR or Lightroom.