komorebi/docs/linux/usage/themes.md

Themes

A theme gives the borders their colors. Instead of choosing the color of each kind of window with komorebic border-colour, a program tells the daemon to take a theme, and the six kinds of border (single, stack, monocle, floating, unfocused and unfocused-locked) take the colors the theme gives them: a Catppuccin theme, a Base16 theme, or a Base16 palette of your own.

There is no komorebic command for it: the daemon takes it from the theme key of komorebi.json, or as a message on its socket, the Theme message, which a program sends with komorebi-client or a script writes as a line of JSON.

use komorebi_client::SocketMessage;
use komorebi_client::send_message;

let theme: SocketMessage = r#"{
    "type": "Theme",
    "content": { "palette": "Catppuccin", "name": "Mocha" }
}"#
.parse()?;
send_message(&theme)?;

The key has the same fields as the message, and wins over border_colours of the file, which has no effect while a theme is set:

{
  "theme": { "palette": "Catppuccin", "name": "Mocha" }
}

The file sets the theme when the daemon starts and when the file changes. A file without theme leaves the one the daemon has.

What a theme gives

palette is the kind of theme (Catppuccin, Base16 or Custom), and name the theme: one of Catppuccin's four, Latte, Frappe, Macchiato and Mocha, or one of the Base16 schemes (Custom has a colours of the sixteen Base16 colors instead). A kind of border that the message does not name takes the theme's default for it:

Border	Catppuccin	Base16
single_border	Blue	Base0D
stack_border	Green	Base0B
monocle_border	Pink	Base0F
floating_border	Yellow	Base09
unfocused_border	Base	Base01
unfocused_locked_border	Red	Base08

The message can name another color of the theme for any of them, as "single_border": "Mauve" for Catppuccin or "single_border": "Base0E" for Base16.

A theme sets the colors that border-colour sets, and replaces them, and the colors set after it replace the theme's. The theme is kept as the current one. The border has to be on and drawn by the effect for any of it to show (Borders).

Palettes from a picture

The Base16 palette of a picture can be made from the picture itself: the same palette generator as komorebi for Windows takes the picture's colors and gives a light or a dark variant. A palette takes seconds to make for a large picture, so each one is kept in $XDG_CACHE_HOME/komorebi (~/.cache/komorebi), in a file named for the picture, a hash of its path, size and time of last change, and the variant. It is made again when the path, the size or the time of change differ. A picture with fewer than eight colors has no palette.