Look carefully at the "Contrast Ratio"
a 400:1 contrast ratio means that each red, green & blue pixel has approximately 400 possible shades, meaning 1200 maximum colours possible from this monitor
HAHAHA, You totally just made that up. I dont think I should even justify this with an answer but I feel bad that you are making stuff up and telling people.
A contrast ratio of 400:1 merely means that the maximum brightness divided by the minumum brightness equals 400. For example the monitor you are looking at is 600:1 and the max brightness is 300 therefore 600=300/x. x=.5. Max= 300 Min=.5.
The monitor you are looking at probably has an 8 bit panel which can display 16.7 million colors. Just a few more than lester calculated at 1200.
The # of bits will calculate total color.
Also Lester each pixel is made up of 3 sub pixels - one green, one red, one blue.