/usr/share/javascript/rainbow/language/ is in libjs-rainbow 1.1.8+ds1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/javascript/rainbow/language/c.js
/usr/share/javascript/rainbow/language/c.min.js
/usr/share/javascript/rainbow/language/css.js
/usr/share/javascript/rainbow/language/css.min.js
/usr/share/javascript/rainbow/language/generic.js
/usr/share/javascript/rainbow/language/generic.min.js
/usr/share/javascript/rainbow/language/html.js
/usr/share/javascript/rainbow/language/html.min.js
/usr/share/javascript/rainbow/language/javascript.js
/usr/share/javascript/rainbow/language/javascript.min.js
/usr/share/javascript/rainbow/language/php.js
/usr/share/javascript/rainbow/language/php.min.js
/usr/share/javascript/rainbow/language/python.js
/usr/share/javascript/rainbow/language/python.min.js
/usr/share/javascript/rainbow/language/ruby.js
/usr/share/javascript/rainbow/language/ruby.min.js
/usr/share/javascript/rainbow/language/shell.js
/usr/share/javascript/rainbow/language/shell.min.js