6 bit vx 8 bit monitor

[SciPunk]

I'm poking around NewEgg and found this monitor:
Acer 19"

One of the reviews had this comment:
Cons: 6 bit color = 16.2M colors. Not a true 8 bit color LCD like Newegg has it list as.

Can somebody tell me (or provide a link to show) the difference between 6 bit color and 8 bit color monitors?

I don't see any mention of bits or number of colors in the specs list. How would I know a 6 bit or an 8 bit monitor when shopping?

Thanks in advance.

 

[chaynz]

http://compreviews.about.com/od/multimedia/a/LCDColor.htm