there are 2 portable devices i am looking at. one claims 65,000 colors (16 bit i believe) the other 262,144 colors (18 bit by a similar diagnosis). would there be any way to test the 2 displays to see if the difference was utilized, or noticeable? the 2 displays are different in their brightness / saturation, so in a side by side comparison with normal pictures, there are too many variables. is there something like an image that an 18 bit color scheme will display correctly and a 16 bit color display will be noticeably poor with? thanks for any guidance.