Color
The human eye can differentiate about 350 000 different colors under normal sunlight conditions, but only 128 gray levels.
If the colors only have different saturation values, the eye can only differentiate 16 yellow tones and 23 different shades of red or violet. A color scanner reads every pixel of a color original with 256 levels each of red, green and blue. This gives 16.8 million different color shades (3 x 8 Bit 256 x 256 x 256).
