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Plain Logs Without Losing Terminal Color

· 2 min read
Erik Osterman
Erik Osterman
Founder @ Cloud Posse

Comparing debug logs is harder when ANSI color escapes appear in the files, even after you ask for plain output. Atmos now consistently honors global color opt-outs and adds an independent log color setting, so you can save plain logs while keeping your terminal UI colored.

The Problem​

As reported in issue #3342, --no-color could still produce colored debug logs in GitHub Actions. Forced color could also override the flag. In our reproduction, 19 of 20 log lines contained ANSI escapes despite the explicit opt-out.

The Fix​

The --no-color flag and a nonempty NO_COLOR environment variable now take precedence throughout startup, logging, and UI output, including when color is forced. GitHub Actions still gets color by default because it supports it.

The new boolean logs.color setting controls Atmos log color independently:

  • true (the default) uses color when available, following existing terminal and CI detection.
  • false removes ANSI escapes from logs, including preformatted log messages.

Use the existing --force-color or ATMOS_FORCE_COLOR=true controls to force color when log color is enabled. Global color opt-outs always win.

How to Use It​

Disable log color in your project configuration:

atmos.yaml
logs:
  color: false

Or save a plain debug log for one invocation while retaining terminal UI colors:

atmos --logs-level=debug --logs-file=/tmp/atmos.log --logs-color=false version

You can also set ATMOS_LOGS_COLOR=false. The command-line flag takes precedence over the environment variable, which takes precedence over configuration. These controls affect Atmos logs; child-process output keeps its own color settings.

To disable color throughout Atmos, including its UI, use:

atmos --logs-level=debug --logs-file=/tmp/atmos.log --no-color version

Get Involved​

See the logging documentation for configuration details. If you encounter another color opt-out regression, open an issue with your command and terminal or CI environment.