Log lines are deliberately coloured

Question

Build logs are coloured (in read chunks, not line-by-line):

build	16-Aug-2021 13:30:01	[91mSLF4J: Class path contains multiple SLF4J bindings.
build	16-Aug-2021 13:30:01	SLF4J: Found binding in [jar:file:/home/java/.cache/coursier/v1/https/repo1.maven.org/maven2/org/slf4j/slf4j-simple/1.7.21/slf4j-simple-1.7.21.jar!/org/slf4j/impl/StaticLoggerBinder.class]
build	16-Aug-2021 13:30:01	SLF4J: Found binding in [jar:file:/home/java/.cache/coursier/v1/https/repo1.maven.org/maven2/ch/qos/logback/logback-classic/1.2.3/logback-classic-1.2.3.jar!/org/slf4j/impl/StaticLoggerBinder.class]
build	16-Aug-2021 13:30:01	SLF4J: Found binding in [jar:file:/home/java/.cache/coursier/v1/https/repo1.maven.org/maven2/org/slf4j/slf4j-log4j12/1.7.10/slf4j-log4j12-1.7.10.jar!/org/slf4j/impl/StaticLoggerBinder.class]
build	16-Aug-2021 13:30:01	[0m[91mSLF4J: See http://www.slf4j.org/codes.html#multiple_bindings for an explanation.
build	16-Aug-2021 13:30:01	[0m[91mSLF4J: Actual binding is of type [org.slf4j.impl.SimpleLoggerFactory]

The question: how to remove `[0m[91m` colouring codes and keep logs plain-text?

Nic Brough -Adaptavist- · Accepted Answer

This is something your build process is putting into the logs, not Bamboo (unless you've modified Bamboos settings to make it do this)

Aleksandr Vinokurov · Accepted Answer

Looks like the cause of the coloured blocks is docker (in Docker task) which colours stderr with red when not using buildkit.

I ended up enabling the later (via env var `DOCKER_BUILDKIT=1`), which ended up Bamboo treating the whole output of the Dockerfile RUN commands as _errors_... but that didn't mess the plaintext logs.