PrismJs Rainbow Parentheses Extension

extension.js

var level = 0
Prism.hooks.add('wrap', function (env) {
  if (env.language == "clojure" && env.type == "punctuation") {
    if (env.content == "(" || env.content == "[" || env.content == "{") {
      level++;
      env.classes.push("rbl" + level);
    }
    if (env.content == ")" || env.content == "]" || env.content == "}") {
      env.classes.push("rbl" + level);
      level--;
    }
  }
});

styles.css

.rbl1 {
  color: #ccc !important;
}

.rbl2 {
  color: #0098e6 !important;
}

.rbl3 {
  color: #e16d6d !important;
}

.rbl4 {
  color: #3fa455 !important;
}

.rbl5 {
  color: #c968e6 !important;
}

.rbl6 {
  color: #999 !important;
}

Sample output from my Clojure blog posts