Themes

First you'll need to place selected themes in your themes directory (i.e ~/.config/helix/themes), the directory might have to be created beforehand.

To use a custom theme add theme = <name> to your config.toml or override it during runtime using :theme <name>.

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

Creating a theme

First 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).

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"

Possible modifiers:

Modifier
bold
dim
italic
underlined
slow\_blink
rapid\_blink
reversed
hidden
crossed\_out

Possible keys:

KeyNotes
attribute
keyword
keyword.directivePreprocessor directives (#if in C)
namespace
punctuation
punctuation.delimiter
operator
special
property
variable
variable.parameter
type
type.builtin
type.enum.variantEnum variants
constructor
function
function.macro
function.builtin
comment
variable.builtin
constant
constant.builtin
string
number
escapeEscaped characters
labelFor lifetimes
module
ui.background
ui.cursor
ui.cursor.insert
ui.cursor.select
ui.cursor.matchMatching bracket etc.
ui.cursor.primaryCursor with primary selection
ui.linenr
ui.linenr.selected
ui.statusline
ui.statusline.inactive
ui.popup
ui.window
ui.help
ui.text
ui.text.focus
ui.menu.selected
ui.selectionFor selections in the editing area
ui.selection.primary
warningLSP warning
errorLSP error
infoLSP info
hintLSP hint

These keys match tree-sitter scopes. We half-follow the common scopes from macromates language grammars with some differences.

For a given highlight produced, styling will be determined based on the longest matching theme key. So it's enough to provide function to highlight function.macro and function.builtin as well, but you can use more specific scopes to highlight specific cases differently.

Color palettes

You can 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.