Hi Peter
There is far more to this than meets the eye (no pun intended!).
The first thing to keep in mind is that each monitor can vary quite wildly, unless you are paying for a 'pro' monitor. Even then, they can vary a little, and will actually change over time...
To get things looking 'correct', you really need to calibrate your monitor. The DataColor Spyder4 is the most common monitor calibration tool these days (both of my monitors get calibrated every few months with one; and yes it can change quite a bit during that time; even with a 'pro' monitor!). With everything calibrated, I run my monitor at 6400K; but this will vary between each monitor (my second monitor doesn't have 'kalvin' measurements for the colour temperature, so can't give a value for that one).
It should also be noted that the colour on the screen can greatly change depending on the lighting in the room, especially with LCD's.
Note, a properly calibrated monitor profile won't actually change how screenshots look for other people. But, it will mean that, on calibrated monitors, it looks pretty much the same. OTOH, on a monitor that is badly needing calibration, it may not look anything close to 'right'. As such, it's more going to effect how your content looks when you create the textures (or when you choose different objects for a map)...
Regards