Comment by cosmos0072

Yep, I am well aware of the `;` vs `:` confusion in both 256 color and 24-bit color control sequences.

Short of hand-coding "which terminal supports which variant" I do not know any standard mechanism to detect that (beyond the well-known $TERM=...-256color and $COLORTERM=truecolor or $COLORTERM=24bit)

I guess I'll have to add command line options to choose among the variants 1...7 you helpfully listed above.

My main use it to render twin directly on X11, which avoids all these issues, and while rendering inside another terminal is important and is not going away, I am OK with a few minor color-related limitations (note: limitations, not bugs) in such setup, especially if the other terminal does not follow the relevant standards