Bug#1037960: The manpages of journalctl should explain bold (or semi-bold), yellow, and blue highlighting/emphasis

[AlMa]

Package: systemd
Version: 252.6-1

The manpage of journalctl doesn't explain the colors yellow and blue and 
the (semi-)bold emphasis of various log entries.  E.g., 
https://www.freedesktop.org/software/systemd/man/journalctl.html 
contains no occurrences of “bold”, “blue”, and “yellow” 
highlighting/emphasis as of now.  Only a generic “lines of level NOTICE 
and higher are highlighted” is stated.  As a result, the I am confused 
when interpreting the output of journalctl -b.

Please explain bold, blue, and yellow in the man pages.

Gratefully,
AlMa