This global minor mode highlights escape sequences in strings and other kinds of literals with `hes-escape-sequence-face' and with `hes-escape-backslash-face'. They inherit from faces `font-lock-regexp-grouping-construct' and `font-lock-regexp-grouping-backslash' by default, respectively. It currently supports `ruby-mode', `emacs-lisp-mode', JS escape sequences in both popular modes, C escapes is `c-mode', `c++-mode', `objc-mode' and `go-mode', and Java escapes in `java-mode' and `clojure-mode'. To enable it elsewhere, customize `hes-mode-alist'. Put this in the init file: (hes-mode)