~snip~
Credit added to the OP
I like the proposal but imagine when there are several external links or even one, but I do not like it to be formatted red as it may not look nice format to others.
Having a warning page with a
Call to action button would be nice I think. The message could be like "you are leaving the forum or opening an external site .......... Do you want to view the site?"
I looked for an example image and found this online:
I do not own the image
I've suggested before that all external links take you to a landing page first as a security measure with a warning to double check the url or something before you leave the site. That would give a buffer or a barrier against phishing links etc.
Feeling you stole the idea before me :-D
I should have give more time to read all the comments carefully.