I am trying to have a better visualization while editing Markdown file in vim, I try to visualize the italic and bold text. However, I found the bold italic text work, while the italic itself doesn't work. It happens outside and insde tmux. I have try use another font, while the italic text itself still not display properly. I don't why the bold italic text can work.

Version of OS, Vim and Terminal emulator:

MacOS : 12.6
Vim : 9.0
Alacritty : 0.11.0

inside alacritty.yml:

    family: Menlo 
  size: 14.0

Inside .vimrc:

set background=dark
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"
syntax on
set termguicolors
colorscheme onedark

Inside .tmux.conf:

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

The terminal emulator does support italic:

Screenshot of italic test

Screenshot of the issue in markdown file:

Bold and italic text in vim

Here is the lines in ~/.vim/colors/onedark.vim that related to markdown italic highlight. enter image description here

  • I have to agree with the answer below; the issue isn't that Vim + Alacritty + Tmux don't support italic, it's that the markdown syntax isn't applying italics correctly in _Italic text_.
    – D. Ben Knoble
    Commented Mar 24, 2023 at 13:35
  • Answers do not belong as edits to questions. Please post an answer below.
    – D. Ben Knoble
    Commented Mar 24, 2023 at 15:46

2 Answers 2


It looks like your italic text shouldn't be blue to begin with, so I would investigate why this is the case.

You should probably start by identifying the actual highlight group used for _Italic text_.

  1. Execute this command:

    :command! SS echo map(synstack(line('.'), col('.')), 'synIDattr(v:val, "name")')
  2. Execute :SS with the cursor on _Italic text_.

    It should echo something like this:


Report back with the actual output.

  • Thank you for suggestion, I have followed the command you provide, it echos ['mkdNonListItemBlock', 'htmlItalic'] instead of ['markdownItalic'], the color is blue because I have use colorscheme for it, I will add this to the question also. I will also try to change the highlight group of ['mkdNonListItemBlock', 'htmlItalic'] to see if any change apply. Commented Mar 24, 2023 at 13:46

I have find a solution. Add highlight group to each items I want it in italic in the color scheme soruce file:

highlight foo cterm=italic

It seems like my color scheme cannot handle with italic text, which require me to add those lines manually. The color scheme I am using are onedark for Vim.

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