Well, in certain 16 color modes, if you select the hue, you then get 16 shades of that hue (mode 9 I think, or mode 11). So a fancy programmer could do Display List tricks and display all 256 colors on 1 screen and we'd get the idea of what the full 256 colors of the 8-bit are officially. 20 years ago, the CRTs weren't as good as today's, neither were the RF converters (mind you that didn't change much). But the goal is I want to know the colors the 8-bit machine is giving. I too had one 20 years ago (1985 to 1987), so I wouldn't even ask that question then ;).
EDIT: This is what G2F gives. Seems G2F dev team thinks the colors aren't shifted 27° angle like A800+ dev thinks, but 24°... And I can't validate this, it could be false. I need someone with the real machine to check for me, LOL!

Here are the MESS 0.115 colors (very different, more saturated):