There is a plugin for Zsh called Fast Syntax Highlighting or simply fsh that adds colors to your shell. The problem is with many terminal themes the comments are invisible.
$ # some comment here
shows like this:
You can simply edit the fsh settings:
~/.config/fsh/overlay.ini
[base]
comment = 101,bold
run this command:
$ fast-theme XDG:overlay
It is permanent and you don’t need to add this to zshrc or anything.
I hope you liked it.