I remember that it had become a standard on PC's and it was called High Color, or something?
I don't. I do however remember that the VGA palette was 18bit.
I think it would have been a good compromise between speed/memory usage and image quality.
How exactly?
To get 18bit you'd still need to have 3 bytes per pixel, or use some kind of weirdo mode where the 6 extra bits would always be used for the next pixel. That'd be prohibilitely complex and slow to work with.
