ct) is a Python script that colors your terminal's output using
regular expressions. It even works with interactive programs, like SSH.
pip3 install chromaterm
Prefix your command with
ct. It's that simple.
ct ssh somewhere
You can also pipe data into
ct, but some programs behave differently when piped,
less would output the entire file.
echo "Jul 14 12:28:19 Message from 18.104.22.168: Completed successfully" | ct
To always highlight a program, set up an alias in your
instance, here's one for
alias ssh="ct ssh"
If you want to highlight your entire terminal, have ChromaTerm spawn your shell by
modifying the shell command in your terminal's settings to
/usr/local/bin/ct /bin/bash --login.
/bin/bash with your shell of choice.
ChromaTerm reads highlight rules from a YAML configuration file, formatted like so:
rules: - description: Obligatory "Hello, World" regex: Hello,?\s+World color: f#ff0000 - description: Spit some facts (emphasize "NOT" so they get it) regex: Pineapple does (NOT) belong on pizza color: 0: bold 1: blink italic underline
The configuration file can be placed in one of the locations below. The first one found is used.
If no file is found, a default one is created in your home directory.
contrib/rules; it has some topic-specific rules that are not included in the defaults.
Optional. It's purely for your sake.
The RegEx engine used is Python's re, but it can be switched to PCRE2 (see relevant section below).
Background and Foreground
The color is a hex string prefixed by
b for background (e.g.
f for foreground (e.g.
In addition to the background and foreground, you can also use
underline. Though, not all terminals support
those styles; you might not see their effects.
Colors can be applied per RegEx group (see the 2nd example rule). Any group in
the RegEx can be referenced, including group
0 (entire match) and
When multiple rules match the same text, ChromaTerm highlights the text with all
of the colors of the matching rules. If you want the text to be highlighted only
by the first rule that matches it, use the
- regex: hello color: bold exclusive: true
In the code above, no other rule will highlight
hello, unless it comes first
and has the
exclusive flag set.
You can define colors in a palette and reference them by name. For instance:
palette: # Created from https://coolors.co/9140f5-bd5df6-e879f6 purple-1: '#9140f5' purple-2: '#bd5df6' purple-3: '#e879f6' rules: - regex: hello color: f.purple-1 - regex: hi color: b.purple-3
When referencing a palette color, prefix it with
b. for background and
PCRE2 library is present, you can use it instead of Python's
engine. When present, an option in
ct -h becomes available.
While the performance improvement is significant (~2x), the two RegEx engines have a few differences; use this option only if you have a good understanding of their unique features.
The default rules work on both engines.
If you've got any questions or suggestions, please open up an issue (always appreciated).
To use ChromaTerm on Windows, you will need to run it with the
Windows Subsystem for Linux (