[...] 

But, until you get manufacturers producing monitors on spec, supplying
those specs, you're not going to get true displays.  Nearly every
monitor has different gamma (the trueness of the greyscale), and nearly
everybody adjusts the contrast and brightness too much.  Monitors need a
light sensor, and something to compute ambient light offset against your
settings, to get true readings.  It's no good trying to colour-grade
photos or printing, when your monitor is displaying black as a
washed-out grey, the monitor gamma is different from your printed media,
and the monitor has a different white tint than your paper and the
ambient light that you're going to look at it under.