MultiTail is an open source ncurses utility that can be used to display multiple logfiles to standard output in a single window or a single shell that shows last few lines of logfiles in a real-time like tail command which split console into more subwindows (much like screen command). It also supports color highlighting, filtering, adding and deleting windows and much more.
Multitail comes with several predefined color highlighting schemas, such as for Apache and Postfix and many more daemons. Because multitail doesn't include a schema for fetchmail, so I created a suitable one for colorized /var/log/fetchmail.
Add the lines to your multitail.conf at the end.
Follow the fetchmail protocol with launch multitail as follows.
$ multitail -cS fetchmail /var/log/fetchmail
If the package is not yet installed on yor machine, multitail can be deployed on Debian and branches as follows.
$ sudo apt install multitail