It's kind of the same thing with people trying to tell me a 300 dpi image as a background is better than a 72dpi (or 96dpi) image.
Bull. :)
That's all the monitor can display. A 300 dpi image will look the same as a 72dpi image -- on your screen.
If you want to print it, then it's an entirely different story. That's where those extra dpi matter.
Colors?
Yeah, you can "see" them all. But you can distinguish between them. It may give a little more depth, but unless you have your monitor calibrated properly and work in an environment where there is no glare, no reflection of any kind - I'd bet you can't actually tell. You'd be guessing. :)

Silke