True Color (24-bit) and italics with alacritty + tmux + vim (neovim)

alacritty-tmux-vim_truecolor.md

True Color (24-bit) and italics with alacritty + tmux + vim (neovim)

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).

Testing colors

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
bash 24-bit-color.sh

Configuration files

⚠️ IMPORTANT ⚠️ Don't set $TERM in your shell (zshrc, bashrc, etc.), but your terminal (alacritty).

Alacritty

In ~/.config/alacritty/alacritty.yml:

env:
  TERM: xterm-256color

tmux

In ~/.tmux.conf (or ~/.config/tmux/tmux.conf):

set -g default-terminal "tmux-256color"
set -ag terminal-overrides ",xterm-256color:RGB"

# Or use a wildcard instead of forcing a default mode.
# Some users in the comments of this gist have reported that this work better.
#set -sg terminal-overrides ",*:RGB"

# You can also use the env variable set from the terminal.
# Useful if you share your configuration betweeen systems with a varying value.
#set -ag terminal-overrides ",$TERM:RGB"

vim

In ~/.vimrc:

" You might have to force true color when using regular vim inside tmux as the
" colorscheme can appear to be grayscale with "termguicolors" option enabled.
if !has('gui_running') && &term =~ '^\%(screen\|tmux\)'
  let &t_8f = "\<Esc>[38;2;%lu;%lu;%lum"
  let &t_8b = "\<Esc>[48;2;%lu;%lu;%lum"
endif

syntax on
set termguicolors
colorscheme yourfavcolorscheme

neovim

If you use ~/.vimrc for your nvim configuration, use the above vim example because it's fully compatible.

💡 neovim recently (Dec 6th 2023) merged some changes that detects termguicolors automatically, so there's no need to set this in an upcoming release. I'll update this notice with a version once released as a public version. This came with the 0.10 release (May 16th 2024).

In ~/.config/nvim/init.vim

set termguicolors
colorscheme yourfavcolorscheme

Or ~/.config/nvim/init.lua:

vim.o.termguicolors = true
vim.cmd'colorscheme yourfavcolorscheme'

Not working correctly ?

Check out the comments below for possible solutions.

And if you found another solution I would really appreciate if you left a comment with instructions and the following information:

• OS/Distro + version
• Vim or Neovim + version
• Terminal name + version

Mentions

Shout-out to the nice folks that provided insightful feedback:

• @mikeslattery native neovim termguicolors support
• @mikeslattery black and white vim colorscheme
• @sahibalejandro env variable inside tmux configuration
• @wonbinbk wildcard in tmux terminal configuration

If vim goes to black and white when setting termguicolors, you may need to add this:

let &t_8f = "\<Esc>[38;2;%lu;%lu;%lum"
let &t_8b = "\<Esc>[48;2;%lu;%lu;%lum"

This isn't a problem with neovim.

@mikeslattery Thanks! I was able to reproduce this. Updated the gist with information :)

THANK YOU. I've tried making this work for years in termite, then alacritty and this FINALLY WORKS.

@andersevenrud , @oxodao I'm glad to help in my small way.

I think this could make a useful dual (n)vim/tmux plugin (a la vim-tmux-navigator), esp if it were verified to work with other popular combinations (e.g. iterm2, gVim).

Thank you!

Thank you!

Thanks!

Thank you very much.

My home brew updated the terminal to Version 0.10.1 and it stopped working :(

Thank you! TERM: xterm-256color was the last piece to the puzzle for me to get it to work properly!

Thanks g!

I'm using Lunar Vim + NeoVim and it's not working for Lunar.
If I open nvim it works, but not lvim.

I'm using Lunar Vim + NeoVim and it's not working for Lunar. If I open nvim it works, but not lvim.

same for me

@mjcc30 @orafaelfragoso LunarVim config is kept in a different directory. Read LunarVim's docs. You can't expect OP to support LunarVim, btw.

I had to set it to

set -g default-terminal "alacritty"
set -ag terminal-overrides ",alacritty:RGB"

OS: macos
Terminal: alacritty
Neovim

Thanks!

The only thing I needed to do was to add set -ag terminal-overrides ",alacritty:RGB" to my .tmux.conf file, nothing else.

macOS v12.3.1
NVIM v0.6.1
alacritty v0.10.1

@sahibalejandro I am guessing that works with Neovim but not Vim.

My experience with Neovim is that more things like this "just work"(tm). Personally, I'm sticking with the original config here as other true-color terminal apps I may install (if any) will be more likely to behave correctly.

Thank you! Life saver.

Thanks, Man, You saved my life…!!

Amazing! Thank you!

Thank You!

This is what worked for me:

alacritty.yml

env:
  TERM: xterm-256color

.tmux.conf

set -g default-terminal 'xterm-256color'
set -as terminal-overrides ',xterm*:Tc:sitm=\E[3m'

Thank you!

This was the only thing that worked for me too, arch linux

@nmdra May we get your .dotfiles ?
Thank you.

Thank you!!

Thank you!!

Thank you! 🍷

Thank you!

I recently discovered that you can use ENV variables inside your tmux.conf so you can have something like:

set -ag terminal-overrides ",$TERM:RGB"

This is useful in the case you're sharing (like me) your tmux.conf between computers and the value of $TERM is different for each one.