I almost always run emacs in a gnu screen session. For iterm-256color, in guixSD I have observed that ...
'screen; emacs -nw' ... supports 16 colors. 'tmux; emacs -nw' ... supports 8. Not only does this seem a bit lame when you consider that VGA supported 256 colors circa 1988, it means that most emacs themes either look awful or aren't usable. I thought I might submit a patch to make 'screen; emacs -nw' support 256 colors. However, if there is a strong preference for tmux, maybe I will switch to tmux and fix that instead. Comments or recomendations would be most welcome. - Thanks, George