Issue description

• It would be nice if there was an ability to change tmux popup color from within the popup (especially while running a script that calls it)
• Went through the manual, where it is mentioned that Panes are not updated while a popup is present..
• I think it would be a good idea to edit at least popup options from within the popup window (if not the pane options)
• Asking this because while calling fzf within tmux popup window, if the tmux popup has border beforehand, and the fzf window also has borders, it would look cluttered. So, if there is an option to change popup options in a popup window, then the popup border is initially deactivated, and after calling the fzf function, the popup border would be activated, (once fzf function call ends), thereby obtaining a more homogeneous appearance
• Current tmux popup window in which a script calling fzf runs: (as seen, there are 2 borders, one for fzf, other one for tmux)

• It's a feature request

Steps to reproduce:

• tmux display-popup 'script'
• script contains command to change tmux popup border color
• Initially the popup window has a border of a certain color
• Unable to change it once the popup window starts

Required information

• tmux version (tmux -V).
  tmux 3.3a
• Platform (uname -sp).
  Darwin arm
• $TERM inside and outside of tmux (echo $TERM).
  • Inside xterm-256color
  • Outside screen-256color
• Logs from tmux (tmux kill-server; tmux -vv new).