Thuli
The official interactive REPL for Farben markup, and for exploring terminal colors in general.
Thuli is Zulu for "quiet" or "peace". A calm, focused space for typing markup and seeing what comes out.
Install
Or from source:
What it is
A small interactive shell, in the spirit of python or irb, but for terminal colors. Type Farben markup, see the rendered output. Inspect tokens and raw ANSI sequences. Register named styles and prefixes on the fly. Browse the full ANSI 256 palette.
It's not limited to Farben either. Thuli is a good general scratchpad for anything terminal-color related: try out RGB values, check how named colors render on your specific terminal, or compare ansi(n) slots side by side.
It also works as a one-shot tool from the shell:
Features
- Interactive REPL loop (read line, render, quit on Ctrl+D)
- Pretty error printing with caret diagnostics, no panics
- Commands:
/help,/quit,/tags,/style,/prefix,/show,/colors,/palette,/theme,/load,/save - One-shot mode via CLI argument
- Fully themeable: all colors and prefixes are overridable via
theme.frb.toml - Per-session style registry: define, load, and save named styles without touching any file
- Tab completion for tag names, commands, and registered styles
Customization
Thuli's appearance is fully driven by named styles. Every color, label, and prefix it uses internally is a thuli::* style entry that can be overridden in theme.frb.toml. The defaults are just defaults.
[]
brand = "[rgb(255,160,0)]"
error = "[bold red]"
text.success = "[dim green]"
[]
error = "!! "
tip = "?? "
You can get the handful of Thuli themes on the thuli-themes repository.
Run /theme inside Thuli to find the config file path on your system. Thuli's theme file follows the FarbenTOML-2026/04 spec.
[!NOTE] you cannot modify or add
thuli::*styles in a thuli session, has to be in the theme file.
Quick Start
Run the REPL:
One-shot mode:
Requires Rust 1.85+.
License
Licensed under either of MIT License or Apache License, Version 2.0 at your option.
Cheers, RazkarStudio. © 2026 RazkarStudio. All rights reserved.