Crie um arquivo chamado tmux-256color-italic.terminfo
e faça tic xterm-256color-italic.terminfo
no terminal. Em seguida, no bashrc
paste export TERM=xterm-256color-italic
tmux-256color-italic|tmux with 256 colors and italic,
sitm=\ePtmux;\e\E[3m\e\, ritm=\ePtmux;\e\E[23m\e\,
use=screen-256color,