question about colours

   Dear Madam or Sir,

   i hope this is the right mail adress for asking for information ... an
   earlyer question there was very kind help from one of you, but i could
   not find the mail to look.
   On my PC there is Debian 12 running, and it seems i don't get
   updates/upgrades for non-system/non-Debian software for quite some time
   now, esp. Emacs, Vim and LaTeX which i use sometimes (learning slowly).
   My question is about settings in Emacs. On my Debian 12 it is version
   28.2 from early 2025 (as i said, no updates from Debian since then).
   I am using the Zenburn theme with a few different colours. I managed to
   set the standard-text colour to a gray and cursor colour to a green
   rectangle in my .emacs file with:

   (set-foreground-color "#b2b2b2")
   (set-cursor-color "#5faf5f")

   I think such set-commands are quite easy to understand and i would like
   also to change the line-numbers (current and oher) to more
   inconspicuous colours, but with online search i couldn't find the right
   commands (like in the examples with "set-xxx 'colour'"), and looking in
   the Zenburn theme file, i got not clever about this.
   Do you have an idea where to look for or perhaps the right command at
   hand?

   Thank you very much in advance and best regards,
   Andreas