With a standard Maven job, I'm not getting ANSI color output from Maven in the console output (Web UI) despite calling Maven with -Dstyle.color=always and having MAVEN_OPTS with -Djansi.force=true. This is with Maven 3.5.4 and 3.6.3, I do get color output when switching to old Maven 3.0.4, which unconditionally outputs some ANSI sequences.

I'm at a loss what to try further and what could be the cause of the problem.

Example console ouput from a build, not showing any color:

Parsing POMs
Modules changed, recalculating dependency graph
Established TCP socket on 28403
[workspace] $ D:\Build\Tools\Java\JDKs\jdk1.8.0/bin/java -Dorg.apache.maven.global-settings=C:\Users\continteg\.m2\settings.xml -Djansi.force=true -cp D:\.j\plugins\maven-plugin\WEB-INF\lib\maven35-agent-1.13.jar;D:\Build\Tools\Java\maven\apache-maven-3.6.3\boot\plexus-classworlds-2.6.0.jar;D:\Build\Tools\Java\maven\apache-maven-3.6.3/conf/logging jenkins.maven3.agent.Maven35Main D:\Build\Tools\Java\maven\apache-maven-3.6.3 D:\.j\war\WEB-INF\lib\remoting-4.3.jar D:\.j\plugins\maven-plugin\WEB-INF\lib\maven35-interceptor-1.13.jar D:\.j\plugins\maven-plugin\WEB-INF\lib\maven3-interceptor-commons-1.13.jar 28403
<===[JENKINS REMOTING CAPACITY]===>channel started
Executing Maven:  -B -f D:\.j\jobs\MyProject\workspace\pom.xml clean install -Dstyle.color=always
[INFO] Scanning for projects...

Note that the following does output color, so the problem is really with Maven's own output not generating color:

            <plugin>
                <groupId>com.github.genthaler</groupId>
                <artifactId>beanshell-maven-plugin</artifactId>
                <version>1.4</version>
                <executions>
                    <execution>
                        <phase>initialize</phase>
                        <goals>
                            <goal>run</goal>
                        </goals>
                        <configuration>
                            <script><![CDATA[
                                print("\u001b[1;31mBold Red\u001b[0m");
                            ]]></script>
                        </configuration>
                    </execution>
                </executions>
            </plugin>