I'm curious... if the RGB values are all accurate, is there a standard color and exposure calibration for paint swatches that is shared across brands?<p>The white point (color temperature) is easy, using whatever light source they're being illuminated with.<p>But what determines whether a particular white is (240, 240, 240) or (250, 250, 250) or (255, 255, 255)? The exposure seems far more arbitrary. Is there some kind of maximally bright matte "reference white" material photographed next to each swatch, that then gets calibrated to (255, 255, 255) or similar?<p>If so, it would be pretty cool if you could buy a reference white chip like that, hold it up to a painted wall in your house, and have an app that could take a photo with both and output the "true" current paint color.