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Colour and style for terminal output, by name rather than by escape code — and one function to take it all back off again.

Version

0.14 zef:raku-community-modules

Depends

nothing outside the core

License

Artistic-2.0

Its own test suite

1 file, green

Checked

2026-08-24 against Raku++ 3.7.0 and Rakudo 2026.08

Where it lives

raku.land · source

Install it #

$ rakupp install Terminal::ANSIColor

zef install Terminal::ANSIColor writes the same store; either installer leaves the module usable by both engines.

What it is for #

A command-line program that says everything in one colour makes the reader do the scanning. One red word and the error is found instantly. The escape codes that do it are short but unmemorable — \e[1;31m — and this module lets you write the names instead:

use Terminal::ANSIColor;

say colored('warning', 'bold yellow').raku;
say colored('ok', 'green').raku;
say color('reset').raku;

"\x[1B][1;33mwarning\x[1B][0m"
"\x[1B][32mok\x[1B][0m"
"\x[1B][0m"

The examples on this page print .raku rather than the string itself, because what is interesting here is the bytes — and because a web page cannot show you a terminal. Run any of them without the .raku and you get the colour.

Two functions do nearly everything. colored($text, $attrs) wraps text and resets afterwards, which is what you want almost always. color($attrs) gives you just the escape sequence, for when you are building a longer line and want to switch attributes partway through — in which case ending with color('reset') is your job.

Attributes, and how they combine #

An attribute string is space-separated words: a foreground colour, a background colour spelled on_…, and any number of styles.

use Terminal::ANSIColor;

my $s = color('bold red on_white') ~ 'ALERT' ~ color('reset');
say $s.raku;
say $s.chars;
say $s.subst(/\e\[ <[\d;]>+ m/, '', :g);

"\x[1B][1;31;47mALERT\x[1B][0m"
19
ALERT

Note the second line. 'ALERT' is five characters; the coloured version is nineteen, because the escape sequences are part of the string. That is the single thing to remember about this module: colour changes .chars. Column alignment computed on a coloured string will be wrong, and so will truncation. Lay out the plain text, then colour it.

The names are the usual set — black red green yellow blue magenta cyan white, their bright_ variants, on_ forms of all of them, and the styles bold, italic, underline, inverse, blink, conceal, strike.

256 colours #

A number is a 256-colour index, and on_ in front of it is the background form. The 38;5;<n> spelling works too, for when you have the raw code from somewhere else:

use Terminal::ANSIColor;

say color('202').raku;
say color('on_17').raku;
say colored('cool', '39').raku;

"\x[1B][38;5;202m"
"\x[1B][48;5;17m"
"\x[1B][38;5;39mcool\x[1B][0m"

An attribute the module does not recognise throws rather than being ignored — Invalid attribute name '38;5;30' for a semicolon-joined form, on both engines — so a typo in a colour name is a loud failure, not a line that quietly comes out plain.

Taking it off again #

colorstrip removes every escape sequence. It is what you want when the same text goes both to a terminal and to a log file, and it is what makes coloured output testable:

use Terminal::ANSIColor;

my $painted = colored('red text', 'red');
say colorstrip($painted);
say colorstrip($painted).chars;
say $painted.chars;

red text
8
17

The honest rule for a program that colours its output: decide once, at startup, whether the destination is a terminal — $*OUT.t answers that — and if it is not, either skip the colouring or colorstrip on the way out. Escape codes in a redirected file are noise, and in a pipe they break the next program's parsing.

use Terminal::ANSIColor;

my %row = ok => 'green', warn => 'yellow', fail => 'bold red';
for %row.keys.sort -> $k {
    say colorstrip(colored($k.uc, %row{$k}));
}

FAIL
OK
WARN

Where the two engines differ #

Nothing on this page, and nothing found off it. Every example prints the same bytes under Raku++ and under Rakudo, twice on each.

What was run to put this page here #

1. Parse — every file of the distribution is parsed by Raku++ itself.
2. Install — rakupp install Terminal::ANSIColor, no dependencies to pull.
3. Test — the distribution's own suite: 1 file, green.
4. Run — every example on this page, twice under each engine, as the site is built.

Nothing had to be fixed for this one. It was among the first four modules the ecosystem campaign measured — in July 2026, when nineteen of the top fifty distributions matched Rakudo's output and nine were outright broken — and it was already in the matching column, along with JSON::Fast, File::Temp and Method::Also. A page that says the engine had to learn nothing is worth having beside the ones that list ten fixes: it is the same measurement, run on a module that happened to ask for nothing the engine did not have.