I have a bunch of Vim colorschemes under my belt.

0-15 are, as I said, a minefield because they are user-customizable: there is no guarantee whatsoever that my user's 1 will be the same dark-ish red as mine… or that it will be dark-ish… or that it will even be vaguely red-ish. It is actually somewhat fun to design colorschemes within those crazy constraints but oh well.

On the other side of the spectrum, truecolors is a nice idea in principle but support is still spotty and inconsistent. In theory, this gives me, the designer, full control over the colors used in the UI, which is a good thing for us and for my users. In fine, if I want my colorscheme to be usable by most users, then I can't blindly rely on this.

Which leaves me with 16-255, which are more widely supported than truecolors and, more importantly, dependable. They have problems, as mentioned in the article, but their _fixed_ nature gives me confidence that the background color of the status-line, for example, will look exactly the same -- and exactly how I want it to look -- in all my user's environments. Which, again, is good for my users and for me. Losing that confidence is what worries me, here.

Like you said, maybe 146 will still be a muted violet —— just not exactly the same -- but I'm not sure about this and I think that, at the minimum, this "feature" should be put behind a checkbox/flag.