Okay, so the help page is clearly wrong.

I just saw, over the remote connection that index #9 is 242,242,242 in windows.

My mac version is then acting weird?

AppPrefs->Interface Theme->Modelspace

The Palette window looks like this: #9 is kind a "chosen", but the color is 192,192,192, not the color of chosen box, which is 242,242,242.

Then, when I hover the cursor over #9, the chosen box, it will show the right index number and the right color values for it.

But when I click #9 box, nothing happens. I can't set my background to #9 (242,242,242), which I really need.

If I go and click #8, it will normally change in the New Color Swatch (If that is the name of those two partially overlapping boxes, again the help page doesn't show this).

But if I after that, try to choose #9, the color will, once again, shift to 192,192,192 and not to #9.
What's happening here?