This should make True Color (24-bit) and italics work in your tmux session and vim when using Alacritty (and should be compatible with any other terminal emulator, including Kitty).
Tested successfully in bash and zsh with latest packages from Arch Linux (with exception of neovim built from source):
2019-07-07- 2021-08-07
- Don't use
&t_8f
,&t_8b
andt_Co
in your vim config - Don't set
$TERM
in your zshrc, bashrc, etc. Configure this in your terminal (alacritty).