Configuration for 24bit true colors terminal with italic

.tmux.conf

set -g default-terminal 'tmux-256color'

# Enable 24 bit true colors
set -ga terminal-overrides ',*:Tc'

.vimrc

set t_ut=                " fix 256 colors in tmux http://sunaku.github.io/vim-256color-bce.html

if has("termguicolors")  " set true colors
    let &t_8f = "\<Esc>[38;2;%lu;%lu;%lum"
    let &t_8b = "\<Esc>[48;2;%lu;%lu;%lum"
    set termguicolors
endif

README.md

• tested to work on macOS iTerm2 and Windows WSL terminals based on mintty.

• tic the terminfo files

• configure the terminal emulator to use xterm-256color-italic

• on ArchLinux (WSL or not), tic'ing tmux-256color.terminfo is generally not needed, it's already provided and can be referred from .tmux.conf without problems

tmux-256color.terminfo

tmux-256color|tmux with 256 colors,
  ritm=\E[23m, rmso=\E[27m, sitm=\E[3m, smso=\E[7m,
  use=xterm-256color, use=screen-256color,

xterm-256color-italic.terminfo

xterm-256color-italic|xterm with 256 colors and italic,
  sitm=\E[3m, ritm=\E[23m,
  use=xterm-256color,