http://content.screencast.com/users/shawnpresser/folders/Jin...
A and B are exactly the same RGB color, even though they appear completely different.
http://www.youtube.com/watch?v=z9Sen1HTu5o
So in truth, yes, the LCD spectrum is limited, but you can still achieve an overall "look and feel" regardless of the smaller gamut. Our perception of any specific color is dominated by other colors around it in the scene.