helix-plus/book/src/themes.md

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", modifiers = ["bold", "italic"] }

where key represents what you want to style, fg specifies the foreground color, bg the background color, and modifiers is a list of style modifiers. bg 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.

Color Name
black
red
green
yellow
blue
magenta
cyan
gray
light-red
light-green
light-yellow
light-blue
light-magenta
light-cyan
light-gray
white

Modifiers

The following values may be used as modifiers.

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

Modifier
bold
dim
italic
underlined
slow_blink
rapid_blink
reversed
hidden
crossed_out

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.

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

Key	Notes
ui.background
ui.background.separator	Picker separator below input line
ui.cursor
ui.cursor.insert
ui.cursor.select
ui.cursor.match	Matching bracket etc.
ui.cursor.primary	Cursor with primary selection
ui.linenr	Line numbers
ui.linenr.selected	Line number for the line the cursor is on
ui.statusline	Statusline
ui.statusline.inactive	Statusline (unfocused document)
ui.statusline.normal	Statusline mode during normal mode (only if editor.color-modes is enabled)
ui.statusline.insert	Statusline mode during insert mode (only if editor.color-modes is enabled)
ui.statusline.select	Statusline mode during select mode (only if editor.color-modes is enabled)
ui.statusline.separator	Separator character in statusline
ui.popup	Documentation popups (e.g space-k)
ui.popup.info	Prompt for multiple key options
ui.window	Border lines separating splits
ui.help	Description box for commands
ui.text	Command prompts, popup text, etc.
ui.text.focus
ui.text.info	The key: command text in ui.popup.info boxes
ui.virtual.ruler	Ruler columns (see the editor.rulers config)
ui.virtual.whitespace	Visible white-space characters
ui.virtual.indent-guide	Vertical indent width guides
ui.menu	Code and command completion menus
ui.menu.selected	Selected autocomplete item
ui.menu.scroll	fg sets thumb color, bg sets track color of scrollbar
ui.selection	For selections in the editing area
ui.selection.primary
ui.cursorline.primary	The line of the primary cursor
ui.cursorline.secondary	The lines of any other cursors
warning	Diagnostics warning (gutter)
error	Diagnostics error (gutter)
info	Diagnostics info (gutter)
hint	Diagnostics hint (gutter)
diagnostic	Diagnostics fallback style (editing area)
diagnostic.hint	Diagnostics hint (editing area)
diagnostic.info	Diagnostics info (editing area)
diagnostic.warning	Diagnostics warning (editing area)
diagnostic.error	Diagnostics error (editing area)

You can check compliance to spec with

cargo xtask themelint onedark  # replace onedark with <name>