PhpStorm has this ability - and I've turned it off.
Too much colors for my blood, and it doesn't look good against Solarized.
One thing I really enjoy about this IDE is the indentation level markers - basically lines draw down to show you where the current scope ends (braces, parens).
I think it would be great if they added it to JS, with their powerful syntax parsing it would be probably trivial to do.
Edit: probably works in their php, django and rails ide-s.