In GNU Emacs there is a feature to highlight matching brackets in code with the same colour.
However when the code which the brackets enclose is really long with severa
The first thing that might help is knowing about this option, if you don't already: blink-matching-paren-distance
. If the sexp is very large then you need to increase the option value, or else paren matching gives up too soon and it shows a mismatch when there is no mismatch.
The second thing that can help is to be sure that blink-matching-paren
and blink-matching-paren-on-screen
are both non-nil
. Then, to see the opening delimiter, just delete the closing delimiter and then type it again. When you insert it, the opening one will be made evident.