When ssh-ing from a friend or family-member’s machine instead of my own, I often find myself using older terminals which support the 256-colour xterm palette but not 24-bit RGB colour. (Rxvt-unicode and the MacOS built-in Terminal.app are examples that spring to mind.)
It’s probably a bit niche for upstream — hopefully non-RGB terminals are a vanishing breed! — but in case anyone else finds themselves in a similar situation, I just tidied up a local patch which adds an option to transparently map RGB colours to an appropriate entry in the 256-colour palette so you don’t have to drop right back to a 16-colour scheme.
https://github.com/arachsys/kakoune/commit/use-palette
It’s only doing simple RGB quantisation to the 6x6x6 cube, with a special case for the 24 scales of grey, but it works pretty well. Here’s kaleidoscope-light 24-bit on the left vs 256-colour on the right:
and here’s base16 24-bit on the left vs 256-colour on the right:
You can see colours aren’t quite identical but aren’t a bad match either: certainly much nicer than being restricted to 16 colours.