Themes

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

Creating a theme

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

The names "default" and "base16_default" are reserved for the builtin themes and cannot be overridden by user defined themes.

The default theme.toml can be found here, and user submitted themes here.

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"

Color palettes

It's recommended define a palette of named colors, and refer to them from 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"

Remember that the [palette] table includes all keys after its header, so you should define the palette after 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 modifiers.

Less common modifiers might not be supported by your terminal emulator.

Note: 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.

Some styles might not be supported by your terminal emulator.

Inheritance

Extend upon 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"

Scopes

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

Syntax highlighting

These keys match tree-sitter scopes.

For a given highlight produced, styling will be determined based on the longest matching theme key. For example, the highlight function.builtin.static would match the key function.builtin rather than function.

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

• attribute - Class attributes, html tag attributes

• type - Types

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

• 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)

• namespace

• markup

  • heading
    • marker
    • 1, 2, 3, 4, 5, 6 - heading text for h1 through h6
  • list
    • unnumbered
    • numbered
  • bold
  • italic
  • 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
  • minus - deletions
  • delta - modifications
    • moved - renamed or moved files/changes

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

You can check compliance to spec with

cargo xtask themelint onedark  # replace onedark with <name>