How to? changing the modeline to show when I'm entering numeric arguments

With my new keyboard often I hit Meta instead of Super, with the result that I start passing numeric args to the next command instead which can be destructive when I don't catch it in time and C-g out of it. Can I change my mode-line during numeric arguments being entered? I already do that when I'm in God Mode, so I would like to copy the same thing. Only, I don't know a mode or other indicator for "I'm entering numeric arguments now". How can I do this?

As a simple option maybe just lowering the `echo-keystrokes` delay would be enough? Otherwise a `pre-command-hook` could be used to warn you. Just as a demonstration: (defun wend/numeric-arg-warning () (when-let ((n (and current-prefix-arg (prefix-numeric-value current-prefix-arg)))) (warn "Numeric arg! %d" n))) (add-hook 'pre-command-hook #'numeric-arg-warning) If you want to change the modeline, a `post-command-hook` would be needed for cleanup, but the timing seems tricky. This doesn't quite work but maybe you can figure it out from here: (defvar-local wend/orig-mode-line-background nil) (defun wend/numeric-arg-warning () (when (and current-prefix-arg (prefix-numeric-value current-prefix-arg)) (setq wend/orig-mode-line-background (face-background 'mode-line)) (set-face-background 'mode-line "red"))) (defun wend/numeric-arg-unwarning () (when (and wend/orig-mode-line-background (not (eq last-command #'self-insert-command))) (set-face-background 'mode-line wend/orig-mode-line-background) (setq wend/orig-mode-line-background nil))) (add-hook 'pre-command-hook #'wend/numeric-arg-warning) (add-hook 'post-command-hook #'wend/numeric-arg-unwarning)

I think echo-keystrokes is a great solution, but it led me to a next question: is it possible to stylize the echo area? I don't see any customization options for "status", but making it a different color would do the trick of calling attention.

Sure. `M-: (progn (message (propertize "QQQQQQQ" 'face 'highlight)) (sleep-for 2))`

any idea how to apply this to certain echo messages, like the numerical args one?

I don't know for sure but I suspect the echoing is done in C code. Otherwise you might be able to add some advice.