ChromaTerm (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, like less would output the entire file.

echo "Jul 14 12:28:19  Message from 1.2.3.4: Completed successfully" | ct

To always highlight a program, set up an alias in your .bash_profile. For instance, here's one for ssh.

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. Replace /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.

• $HOME/.chromaterm.yml
• $XDG_CONFIG_HOME/chromaterm/chromaterm.yml ($XDG_CONFIG_HOME defaults to $HOME/.config)
• /etc/chromaterm/chromaterm.yml

If no file is found, a default one is created in your home directory.

Check out 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).

The color is a hex string prefixed by b for background (e.g. b#123456) and f for foreground (e.g. f#abcdef).

In addition to the background and foreground, you can also use blink, bold, invert, italic, strike, and 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 named groups.

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 exclusive flag.

- 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 f. for foreground.

If the PCRE2 library is present, you can use it instead of Python's re 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 (WSL)