Earlier quoted context omitted.
C64 hi-res graphics was 320x200, two selectable colors for each 8x8 char sized block. So 16 colors on the screen, but... See: https://www.c64-wiki.com/wiki/High_Resolution
That makes much more sense, thanks! I mixed something up there, or I just misunderstood the marketing material as a kid.
You can get far past those limitations with nufli, which uses sprite layers and some other trickery.
https://web.archive.org/web/20170104014040/http://c64pixels....
The images really look like that on C64 screen, with absolutely no flickering etc.