Use true Solarized colors from within tmux in iTerm2

Question

How can I use vim (8.2) within a tmux session in iTerm2, with Solarized colors? I have the Solarized colors set with my terminal, as suggested in the docs for vim solarized colors plugin. When I call Vim from within a tmux session, the colors are clearly different, as below - in particular there's a jarring change in the background color in some places. How can I specify that the appearance is the same, regardless of whether I'm running from within a tmux session?

Note that I do not want to use a 256 color palette.

Normal vim session

When running from within tmux

Answer 1

Try adding to ~/.tmux.conf:

set -g default-terminal "tmux-256color"
set -ag terminal-overrides ',*:RGB'
# for older tmux
# set -ag terminal-overrides ',*:Tc'

Might be interesting:

• https://github.com/tmux/tmux/issues/622
• https://github.com/tmux/tmux/issues/34