Themes

To use a theme add theme = "<name>" to the top of your config.toml file, or select it during runtime using :theme <name>.

Creating a theme

Create a file with the name of your theme as the file name (i.e mytheme.toml) and place it in your themes directory (i.e ~/.config/helix/themes or %AppData%\helix\themes on Windows). The directory might have to be created beforehand.

💡 The names "default" and "base16_default" are reserved for built-in themes and cannot be overridden by user-defined themes.

Overview

Each line in the theme file is specified as below:

key = { fg = "#ffffff", bg = "#000000", underline = { color = "#ff0000", style = "curl"}, modifiers = ["bold", "italic"] }

Where key represents what you want to style, fg specifies the foreground color, bg the background color, underline the underline style/color, and modifiers is a list of style modifiers. bg, underline and modifiers can be omitted to defer to the defaults.

To specify only the foreground color:

key = "#ffffff"

If the key contains a dot '.', it must be quoted to prevent it being parsed as a dotted key.

"key.key" = "#ffffff"

For inspiration, you can find the default theme.toml here and user-submitted themes here.

Using the linter

Use the supplied linting tool to check for errors and missing scopes:

cargo xtask themelint onedark # replace onedark with <name>

The details of theme creation

Color palettes

It's recommended to define a palette of named colors, and refer to them in the configuration values in your theme. To do this, add a table called palette to your theme file:

"ui.background" = "white"
"ui.text" = "black"

[palette]
white = "#ffffff"
black = "#000000"

Keep in mind that the [palette] table includes all keys after its header, so it should be defined after the normal theme options.

The default palette uses the terminal's default 16 colors, and the colors names are listed below. The [palette] section in the config file takes precedence over it and is merged into the default palette.

Modifiers

The following values may be used as modifier, provided they are supported by your terminal emulator.

💡 The underlined modifier is deprecated and only available for backwards compatibility. Its behavior is equivalent to setting underline.style="line".

Underline style

One of the following values may be used as a value for underline.style, providing it is supported by your terminal emulator.

Inheritance

Extend other themes by setting the inherits property to an existing theme.

inherits = "boo_berry"

# Override the theming for "keyword"s:
"keyword" = { fg = "gold" }

# Override colors in the palette:
[palette]
berry = "#2A2A4D"

Rainbow

The rainbow key is used for rainbow highlight for matching brackets. The key is a list of styles.

rainbow = ["#ff0000", "#ffa500", "#fff000", { fg = "#00ff00", modifiers = ["bold"] }]

Colors from the palette and modifiers may be used.

Scopes

The following is a list of scopes available to use for styling:

Syntax highlighting

These keys match tree-sitter scopes.

When determining styling for a highlight, the longest matching theme key will be used. For example, if the highlight is function.builtin.static, the key function.builtin will be used instead of function.

We use a similar set of scopes as Sublime Text. See also TextMate scopes.

• attribute - Class attributes, HTML tag attributes

• type - Types

  • builtin - Primitive types provided by the language (int, usize)
  • enum
    • variant

• constructor

• constant (TODO: constant.other.placeholder for %v)

  • builtin Special constants provided by the language (true, false, nil etc)
    • boolean
  • character
    • escape
  • numeric (numbers)
    • integer
    • float

• string (TODO: string.quoted.{single, double}, string.raw/.unquoted)?

  • regexp - Regular expressions
  • special
    • path
    • url
    • symbol - Erlang/Elixir atoms, Ruby symbols, Clojure keywords

• comment - Code comments

  • line - Single line comments (//)
  • block - Block comments (e.g. (/* */)
    • documentation - Documentation comments (e.g. /// in Rust)

• variable - Variables

  • builtin - Reserved language variables (self, this, super, etc.)
  • parameter - Function parameters
  • other
    • member - Fields of composite data types (e.g. structs, unions)

• label

• punctuation

  • delimiter - Commas, colons
  • bracket - Parentheses, angle brackets, etc.
  • special - String interpolation brackets.

• keyword

  • control
    • conditional - if, else
    • repeat - for, while, loop
    • import - import, export
    • return
    • exception
  • operator - or, in
  • directive - Preprocessor directives (#if in C)
  • function - fn, func
  • storage - Keywords describing how things are stored
    • type - The type of something, class, function, var, let, etc.
    • modifier - Storage modifiers like static, mut, const, ref, etc.

• operator - ||, +=, >

• function

  • builtin
  • method
  • macro
  • special (preprocessor in C)

• tag - Tags (e.g. <body> in HTML)

  • builtin

• namespace

• special

• markup

  • heading
    • marker
    • 1, 2, 3, 4, 5, 6 - heading text for h1 through h6
  • list
    • unnumbered
    • numbered
    • checked
    • unchecked
  • bold
  • italic
  • strikethrough
  • link
    • url - URLs pointed to by links
    • label - non-URL link references
    • text - URL and image descriptions in links
  • quote
  • raw
    • inline
    • block

• diff - version control changes

  • plus - additions
    • gutter - gutter indicator
  • minus - deletions
    • gutter - gutter indicator
  • delta - modifications
    • moved - renamed or moved files/changes
    • gutter - gutter indicator

Interface

These scopes are used for theming the editor interface:

• markup
  • normal
    • completion - for completion doc popup UI
    • hover - for hover popup UI
  • heading
    • completion - for completion doc popup UI
    • hover - for hover popup UI
  • raw
    • inline
      • completion - for completion doc popup UI
      • hover - for hover popup UI