Installation

Add to Your Project

cargo add opaline

This enables the default features: builtin-themes, gradients, and ratatui.

Feature Flags

Opaline uses feature flags to keep the dependency tree lean. Enable only what you need:

[dependencies]
# Default: builtins + gradients + ratatui adapter
opaline = "0.4"

# Minimal: just the core theme engine
opaline = { version = "0.4", default-features = false }

# With CLI colored output
opaline = { version = "0.4", features = ["cli"] }

# With global theme singleton
opaline = { version = "0.4", features = ["global-state"] }

# Everything
opaline = { version = "0.4", features = [
    "builtin-themes", "gradients", "ratatui",
    "cli", "crossterm", "owo-colors", "css",
    "syntect", "egui",
    "global-state", "discovery", "widgets"
] }

Feature	Default	Description
builtin-themes	yes	39 embedded TOML themes via include_str!
gradients	yes	Multi-stop gradient support
ratatui	yes	From impls for ratatui::style::{Color, Style}
cli	no	colored crate adapter for ANSI terminal output
crossterm	no	Direct crossterm Color/ContentStyle adapter
owo-colors	no	Zero-allocation terminal coloring via owo-colors
css	no	CSS custom properties + classes generation
syntect	no	Syntax highlighting theme generation
egui	no	Color32/Visuals adapter for egui
global-state	no	Process-wide current()/set_theme() singleton
discovery	no	Load user themes from ~/.config/<app>/themes/
widgets	no	Theme selector widget with live preview

See Feature Flags for the full feature interaction matrix.

Requirements

• Rust edition 2024 (MSRV 1.85)
• ratatui-core 0.1 (pulled automatically when ratatui feature is enabled)

Verify Installation

use opaline::Theme;

fn main() {
    let theme = Theme::default();
    println!("Loaded: {} ({})", theme.meta.name,
        if theme.is_dark() { "dark" } else { "light" });
}

This should print: Loaded: SilkCircuit Neon (dark)