Cool thanks for replies everyone
Yeah I've been experimenting with colours, working out all the permutations of increasing rgb values by 4 was fun. My webpage is nearly 40 meg that displays them all so can see how this would suck memory.
Been quite interesting actually to learn about how colours work in general.
64x64x64 is
262,144 colors
Which for the 25% savings on memory compared to 8bit per channel is actually Pretty Dang Good since its "possible" to notice the difference, but its much less pronounced than it is with 15/16 bit graphics (im pretty sure my netbook has a 16 bit display and just hardware downconverts 24bit in realtime because it will stipple colors that should be solid).
So thats like getting 25% of your memory back for free, back in the days of 512kb conventional memory and (maybe) 2Mb of Ram that was a killer deal.
The Trident SVGA video card my dad had installed on our x286 had 1Mb of video ram. That was pretty dam awesome though it was entirely incapable of displaying HiColor or TrueColor.
Im not sure but I think the original NES gaming system, based on my observations with using an old emulator that allowed me to mess with the colors . . . actually used 4 bits per channel or worse.
It only displayed 16 colors at a time, but from the color mixer selection it seemed that all of the colors it could switch out were actually mapped or had noticeable increments on its sliders.
Even a 16 color EGA display can adjust the individual color values usually by 64 shades each. So the original NES game system is actually a little bit less capable than EGA is. Though with the optimized way they programmed the games back then you really wouldn't notice (like the siezure inducing screen flashes, and the palette cycling on those zelda fireballs and sword bolts that somehow looked pretty awesome but at 60hz framerate made them look ultraviolet and stuff).