Coloring like what you're talking about is done on GitHub and Stack Exchange, not so much the error highlighting, though it can make some syntax errors more obvious.
I doubt it would encourage people to use code tags.
I doubt it would encourage people to use code tags
You may be right, but it would look pretty.!
and your right, Git and such have a very feature rich viewer.
To much for this site I suspect, but aspects could work.
I wonder if the java viewer I have will do it on C.
The web editor CREATE has some of those features already.
They seem to integrate closely with the regular IDE teams as some of the web features have migrated to the regular IDE.
Maybe worth a mention on that side of the fence (so to speak)