diff --git a/lib/colors.js b/lib/colors.js
index bfa5ded5..6d74a44a 100644
--- a/lib/colors.js
+++ b/lib/colors.js
@@ -31,7 +31,7 @@ const colored = {
   greyMessage: gray
 }
 
-function resolveCustomColored (customColors) {
+function resolveCustomColoredColorizer (customColors) {
   return customColors.reduce(
     function (agg, [level, color]) {
       agg[level] = typeof availableColors[color] === 'function' ? availableColors[color] : white
@@ -71,7 +71,7 @@ coloredColorizer.message = colored.message
 coloredColorizer.greyMessage = colored.greyMessage
 
 function customColoredColorizerFactory (customColors) {
-  const customColored = resolveCustomColored(customColors)
+  const customColored = resolveCustomColoredColorizer(customColors)
 
   const customColoredColorizer = function (level, opts) {
     return colorizeLevel(level, customColored, opts)
@@ -88,6 +88,7 @@ function customColoredColorizerFactory (customColors) {
  *
  * @param {boolean} [useColors=false] When `true` a function that applies standard
  * terminal colors is returned.
+ * @param {array[]} [customColors] Touple where first item of each array is the level index and the second item is the color
  *
  * @returns {function} `function (level) {}` has a `.message(str)` method to
  * apply colorization to a string. The core function accepts either an integer
diff --git a/lib/utils.js b/lib/utils.js
index 90ac2e00..b8dbf93c 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -217,8 +217,10 @@ function prettifyErrorLog ({
  * @param {object} input.log The log object.
  * @param {function} [input.colorizer] A colorizer function that accepts a level
  * value and returns a colorized string. Default: a no-op colorizer.
- * @param {string} [levelKey='level'] The key to find the level under.
+ * @param {string} [input.levelKey='level'] The key to find the level under.
  * @param {function} [input.prettifier] A user-supplied formatter to be called instead of colorizer.
+ * @param {object} [input.customLevels] The custom levels where key as the level index and value as the level name.
+ * @param {object} [input.customLevelNames] The custom level names where key is the level name and value is the level index.
  *
  * @returns {undefined|string} If `log` does not have a `level` property then
  * `undefined` will be returned. Otherwise, a string from the specified
@@ -242,12 +244,15 @@ function prettifyLevel ({ log, colorizer = defaultColorizer, levelKey = LEVEL_KE
  * @param {function} [input.colorizer] A colorizer function that has a
  * `.message(str)` method attached to it. This function should return a colorized
  * string which will be the "prettified" message. Default: a no-op colorizer.
+ * @param {string} [input.levelLabel='levelLabel'] The label used to output the log level
+ * @param {string} [input.levelKey='level'] The key to find the level under.
+ * @param {object} [input.customLevels] The custom levels where key as the level index and value as the level name.
  *
  * @returns {undefined|string} If the message key is not found, or the message
  * key is not a string, then `undefined` will be returned. Otherwise, a string
  * that is the prettified message.
  */
-function prettifyMessage ({ log, messageFormat, messageKey = MESSAGE_KEY, colorizer = defaultColorizer, levelLabel = LEVEL_LABEL, customLevels, levelKey = LEVEL_KEY }) {
+function prettifyMessage ({ log, messageFormat, messageKey = MESSAGE_KEY, colorizer = defaultColorizer, levelLabel = LEVEL_LABEL, levelKey = LEVEL_KEY, customLevels }) {
   if (messageFormat && typeof messageFormat === 'string') {
     const message = String(messageFormat).replace(/{([^{}]+)}/g, function (match, p1) {
       // return log level as string instead of int
diff --git a/test/basic.test.js b/test/basic.test.js
index 26a71498..b7467cf8 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -627,10 +627,10 @@ test('basic prettifier tests', (t) => {
     t.plan(7)
     const expectedLines = [
       '    msg: {',
-      '      "a": "[Circular]",',
       '      "b": {',
       '        "c": "d"',
-      '      }',
+      '      },',
+      '      "a": "[Circular ~]"',
       '    }'
     ]
     const pretty = prettyFactory()
diff --git a/test/lib/colors.test.js b/test/lib/colors.test.js
index 89e5866b..b4d83b6f 100644
--- a/test/lib/colors.test.js
+++ b/test/lib/colors.test.js
@@ -76,7 +76,7 @@ const testColoringColorizer = getColorizer => async t => {
   t.equal(colorized, '\u001B[90mfoo\u001B[39m')
 }
 
-const testCustomColoringColorizer = getColorizer = async t => {
+const testCustomColoringColorizer = getColorizer => async t => {
   const customLevels = {
     0: 'INFO',
     1: 'ERR',
@@ -120,4 +120,4 @@ test('returns default colorizer - public export', testDefaultColorizer(getColori
 test('returns colorizing colorizer - private export', testColoringColorizer(getColorizerPrivate))
 test('returns colorizing colorizer - public export', testColoringColorizer(getColorizerPublic))
 test('returns custom colorizing colorizer - private export', testCustomColoringColorizer(getColorizerPrivate))
-test('returns custom colorizing colorizer - public export', testCustomColoringColorizer(getColorizerPublic))
\ No newline at end of file
+test('returns custom colorizing colorizer - public export', testCustomColoringColorizer(getColorizerPublic))