if i'm not mistaken, all the graphics used in the game is 8-bit, any chance that this will be changed in the future patches, to e.g. 24-bit?
I don't see why anyone would ever need more than 8 bits of color, or 640K of system memory either, for that matter...
On a more serious note, I don't really think that the color depth is an issue. The original graphics may have been created with 8-bit limits, but as far as I know, the engine simply calls for a bmp file, and doesn't concern itself with the color depth that the file was originally created under.
In short, if you want to mod your own graphics, go ahead. However, to recreate all of the pre-existing graphics just to give them a little more color, would be more trouble than they're worth, IMO.