macOS has ncurses version 5.7 which does not ship the terminfo description for tmux. There're two ways that can help you to solve this problem.
Instead of tmux-256color, use screen-256color which comes with system. Place this command into ~/.tmux.conf or ~/.config/tmux/tmux.conf(for version 3.1 and later):
This should make True Color (24-bit) and italics work in your tmux session and vim/neovim when using Alacritty (and should be compatible with any other terminal emulator, including Kitty).
Running this script should look the same in tmux as without.
curl -s https://gist.githubusercontent.com/lifepillar/09a44b8cf0f9397465614e622979107f/raw/24-bit-color.sh >24-bit-color.sh
| @echo off | |
| :: this batch file: | |
| :: 1. sets the username, password, and web proxy server in npm, git, and the windows environment. | |
| :: 2. tells nom which version of c++ compiler and where it is | |
| :: constants to set for your system | |
| set npm_location=d:\nodejs\npm.cmd | |
| :: these are just reminders for me and the things I was using on my system when I had this issue |