---
title: Fix broken Vim Themes
date: 2022-04-14
description: A working solution for fixing broken Vim colour themes using Neovim, a proper terminal, and correct tmux configuration.
tags: [vim, neovim]
---

I've been around the houses on this problem long enough, and after many years of trying various tricks and having them fail I decided to document an actual working solution.

1. Install a terminal that has good colour support (e.g. [Alacritty](https://alacritty.org/))
1. Install a better Vim (i.e. [Neovim](https://neovim.io)) †

> [!INFO]
> † This should still work with standard Vim, but actually Neovim has so many performance improvements, and quality of life plugins it's not worth fighting for purity (trust me, I had been using standard vim and the standard macOS terminal app for 10 years before admitting I was fighting the tide).

Now that you have the right tools, let's explain the configuration.

**~/.config/nvim/init.vim**

```viml
" this will tell Neovim to enable 24bit true color
if (has("termguicolors"))
 set termguicolors
endif
```

**~/.bashrc**

```bash
# this isn't necessary when using Neovim in an appropriate terminal, 
# but it will help when running Neovim inside of tmux.
export TERM="xterm-256color"
```

**~/.tmux.conf**

```bash
set-option -g default-terminal 'screen-256color-bce'
set-option -ga terminal-overrides ",xterm-256color:Tc"
```

The tmux manual states that `default-terminal` should be set to `screen`, `tmux` or a derivative of them, which is why this doesn't get set to the same value (`xterm-256color`) that `TERM` has in the `.bashrc` file.

Additionally, we use the `-bce` suffix (rather than just setting `screen-256color`) because otherwise tmux won't use a transparent background. Having a transparent background allows the terminal colour palette to be utilised and this helps Vim themes to display correctly.

Lastly, `terminal-overrides` let's you configure tmux to know about terminal capabilities it otherwise might not be able to detect by itself. So this is why we set it to the same value (`xterm-256color`) that `TERM` has in the `.bashrc` file.