[cb321]

> do the right thing by checking if the standard output is an actual tty (isatty)

This is a very questionable heuristic. I'm not sure the exact date that support began, but I have been piping color output to `less -r/-R` for decades. This can be nice even for less than multi-terminal-page output just for "search".

isatty(stderr) would actually be more accurate for my specific use cases for when I don't `|&` or maybe even `isatty(stdin)`, but those are also imperfect heuristics.

The point is, since "auto" is a questionable heuristic, it is not so crazy/wrong to just default to color-on and have an off switch and that off switch is what NO_COLOR is about (as explained by the very first sentence in the linked article). Desirable defaults ultimately depend upon the distribution of your user's tastes (as always, more|less).