This issue is the same issue than JENKINS-40762, but now happening in the ansiColor plugin.

When a single pipeline step generates a lot of logging all at once, the log on disk might repeat itself.

This persists between Jenkins restarts and can only be stopped by stopping Jenkins, deleting the $JENKINS_HOME/jobs/[job]/build/[build id] directory, and starting Jenkins again.
STR:

1. Create a new pipeline job with the following pipeline script definition:

ansiColor('xterm') {
    node ("linux-slave") { 
        sh ''' 
            export i=1; 
            while [ "$i" -lt "50000" ]; 
            do 
                i=$((i+1)); 
                echo "$i: this is test line content.this is test line content.this is test line content.this is test line content." 
            done 
        ''' 
    } 
}

2. Run the job.

Expected result:
Job terminates eventually.
There are around 200.000 lines in the log files

Actual result:
Job does not terminate, or terminate with much more than 200.000 lines duplicating some od the consoleoutput logs

Note: To reproduce this issue, I would recommend using a dedicated agent instead of directly using the master agent.