For the size of the screen and resolution that the CFAF320240F series has it is more efficient to use 65K colors rather than 262K colors. The controller and TFT panel support 262K colors but it is essentially "overkill". Why? you only have 320 * 240 * RGB pixels to work with, or 76800.
To clarify:
1) 65k colors = 16 bit. This is done by using 32 Red, 64 Green and 32 Blue (2^5=32, 2^6=64, 5+6+5=16 bits, 32x64x32=65536 colors)
2) 262k colors = 18 bit. This is done by using 2^6 colors in each Red, Green, and Blue channel. (2^6=64, 64x64x64=262144)
NOTE: The 16 bit / 65K color configuration, green has 2^6 different shades / colors. More than the red or blue. Why? The human eye is most sensitive to green. So with 65k colors you have in fact just as good green as with 262k colors. Only the red and blue can be problematic.
On a small color TFT, like the modules that we have manufactured, sell, and support you can't fit 262144 colors on the display. Since the most important color to human eye is green, you will "technically" have the same amount of colors when running 65k or 262k.
In summary, you "can" run 262K colors but you will have just as good of an image coding at 65K. There will be less overhead on your micro-controller, and less code space for your images as a bonus!
Hope that helps.
