Add GZ_CONSOLE_COLOR env variable to control terminal color output

[BhuvanB404]

🎉 New feature

Closes #611

Summary

If the env variable is yes , the ANSI color codes are on for logging. When it is no, it disables ANSI colors

-- Testing GZ_CONSOLE_COLOR = yes ---
^[[32m(2026-03-06 13:16:01.402) [info] [test_color.cc:10] This is an info message
^[[m^[[33m^[[1m(2026-03-06 13:16:01.402) [warning] [test_color.cc:11] This is a warning message
^[[m^[[31m^[[1m(2026-03-06 13:16:01.402) [error] [test_color.cc:12] This is an error message

after turning the color_mode to no the outputs do not contain the asci color codes.

--- Testing GZ_CONSOLE_COLOR = no---
(2026-03-06 13:16:01.404) [info] [test_color.cc:10] This is an info message
(2026-03-06 13:16:01.404) [warning] [test_color.cc:11] This is a warning message
(2026-03-06 13:16:01.404) [error] [test_color.cc:12] This is an error message
(2026-03-06 13:16:01.404) [debug] [test_color.cc:13] This is a debug message

Need to add a logger wrapper in gz-utils to change the color_mode through sink. that is done in this pr -> gazebosim/gz-utils#205

Test it

Checklist

• Signed all commits for DCO
• Added a screen capture or video to the PR description that demonstrates the feature
• Added tests
• Added example and/or tutorial
• Updated documentation (as needed)
• Updated migration guide (as needed)
• Consider updating Python bindings (if the library has them)
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[Copilot]

Pull request overview

Adds a new environment variable (GZ_CONSOLE_COLOR) to control whether console log output includes ANSI color codes, addressing the need to disable unreadable escape sequences in CI consoles (issue #611).

Changes:

• Read GZ_CONSOLE_COLOR during gz::common::Console::Init and set spdlog console color mode to always / never.
• Emit a warning when GZ_CONSOLE_COLOR is set to an unrecognized value.
• Document GZ_CONSOLE_COLOR in the repository README.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
src/Console.cc	Parses GZ_CONSOLE_COLOR and configures console sink color mode accordingly.
README.md	Documents how to use GZ_CONSOLE_COLOR to enable/disable color output.

---

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[Copilot]

GZ_CONSOLE_COLOR only recognizes yes/no. The linked issue / common patterns in this repo suggest accepting additional boolean-style values (e.g., 0/1, true/false) and ideally auto (leave default behavior) to avoid surprising users who follow gtest-style env vars.

Suggested change

	if (value == "yes")
	{
	Console::Root().SetConsoleColorMode(spdlog::color_mode::always);
	}
	else if (value == "no")
	{
	Console::Root().SetConsoleColorMode(spdlog::color_mode::never);
	}
	else
	{
	Console::Root().RawLogger().log(spdlog::level::warn,
	"Valid values are: yes, no.");
	if (value == "yes" || value == "true" || value == "1" || value == "on")
	{
	Console::Root().SetConsoleColorMode(spdlog::color_mode::always);
	}
	else if (value == "no" || value == "false" || value == "0" || value == "off")
	{
	Console::Root().SetConsoleColorMode(spdlog::color_mode::never);
	}
	else if (value == "auto")
	{
	// Leave console color mode at its default behavior.
	}
	else
	{
	Console::Root().RawLogger().log(spdlog::level::warn,
	"GZ_CONSOLE_COLOR: valid values are: yes, no, true, false, 1, 0, on, off, auto.");

[BhuvanB404]

Is there a need to handle all cases? making it work for standard yes no should be fine I believe

[Copilot]

README documents only yes/no, but the implementation is intended to address the broader “disable color output” use case (and the issue suggests gtest-like behavior). If you add support for 0/1 and/or auto, please document those here; otherwise consider explicitly stating that only yes/no are supported and that other values will be ignored with a warning.

Suggested change

	Only the values `yes` and `no` are recognized; other values are ignored.

[azeey]

Thanks for the contribution @BhuvanB404! Sorry I didn't get a chance to respond to your comment on #611. That issue was created while gz-common had it's own implementation of console logging. Now that we are using spdlog, our Jenkins logs do not contain the color codes (see https://build.osrfoundation.org/view/gz-jetty/job/gz_common-ci-gz-common7-noble-amd64/58/consoleText search for 1;31m).

However, we still have the problem on Harmonic (gz-common5) and Fortress (ign-common4) (see https://build.osrfoundation.org/view/gz-harmonic/job/gz_common-ci-gz-common5-noble-amd64/187/consoleText and search for 1;31m). So, could you please rework your PR to target gz-common5? Thanks!