Need a color palette? Do you have to hand-roll it?

Palette Core is a theme engine that turns TOML palette definitions into CSS, terminal, egui, syntect, JSON, and WASM exports.

use palette_core::load_preset;

let palette = load_preset("tokyonight").unwrap();
let css = palette.to_css();

:root {
  --bg: #1A1B26;
  --fg: #C0CAF5;
  --error: #DB4B4B;
  --syn-keyword: #BB9AF7;
  --ed-cursor: #C0CAF5;
  /* ... 136+ variables total */
}

Install

cargo add palette-core

Usage

Terminal

use palette_core::load_preset;
use palette_core::terminal::to_terminal_theme;

let palette = load_preset("catppuccin").unwrap();
let theme = to_terminal_theme(&palette);

Theme variants

Variants inherit from a base and override only what changes.

[meta]
name = "My Dark Warm"
preset_id = "my_dark_warm"
inherits = "tokyonight"

[base]
background = "#24283b"

Contrast validation and auto-fix

use palette_core::{load_preset, ContrastLevel};
use palette_core::contrast::validate_palette;

let palette = load_preset("tokyonight").unwrap();
let violations = validate_palette(&palette, ContrastLevel::AaNormal);

// Auto-fix: nudge failing foregrounds to meet WCAG at resolve time
let resolved = palette.resolve_with_contrast(ContrastLevel::AaNormal);

Documentation

The guide covers rendering targets, theme switching, custom presets, color manipulation, gradients, platform overrides, and WASM bindings.

31 presets ship built-in — Catppuccin, TokyoNight, Dracula, Nord, Gruvbox, and more. Golden Hour is an original warm-toned family (light, dusk, twilight) exclusive to palette-core. Themes can define gradients with OKLab/OKLCH interpolation and CSS linear-gradient() export. Optional feature flags enable terminal, egui, syntect, snapshot, platform, and wasm targets.

Demos

See p3-demo for a TUI theme picker and a side-by-side CSS preview, with a WASM demo in progress.

License

Licensed under Apache-2.0 or MIT at your option.