Add keys color based on the level

lib/Default.coffee

@@ -73,7 +73,8 @@ module.exports =
 
   generateTypeMessage: (type) ->
     (message...) ->
-      message = @format message
+      color = @types[type].color
+      message = @format message, color
       message = @generateMessage type, message
       @transport message if message
       this
@@ -90,7 +91,9 @@ module.exports =
     return false if @level is CONST.MUTED
     @types[type].level <= @types[@level].level
 
-  format: (messages) -> formatUtil.apply null, messages
+  format: (messages, color) ->
+    messages.push color
+    formatUtil.apply null, messages
 
   keyword: null
   diff: false

lib/Format.coffee

@@ -1,13 +1,15 @@
 'use strict'
 
+chalk = require 'chalk'
+
 REGEX =
   escape: /%{2,2}/g
   type: /(%?)(%([jds]))/g
 
 hasWhiteSpace = (s) ->
   s.indexOf(' ') isnt -1
 
-serialize = (obj, key) ->
+serialize = (color, obj, key) ->
   # symbols cannot be directly casted to strings
   if typeof key is 'symbol'
     key = key.toString()
@@ -34,22 +36,24 @@ serialize = (obj, key) ->
       j = 0
       l = obj[keys[i]].length
       while j < l
-        msg += serialize(obj[keys[i]][j])
+        msg += serialize(color, obj[keys[i]][j])
         if j < l - 1
           msg += ' '
         j++
       msg += ']'
     else if obj[keys[i]] instanceof Date
       msg += keys[i] + '=' + obj[keys[i]]
     else
-      msg += serialize(obj[keys[i]], keys[i])
+      msg += serialize(color, obj[keys[i]], chalk[color](keys[i]))
     if i < length - 1
       msg += ' '
     i++
   msg
 
 format = (fmt) ->
   args = Array::slice.call(arguments, 1)
+  color = args.pop()
+
   if args.length
     fmt = fmt.replace(REGEX.type, (match, escaped, ptn, flag) ->
       arg = args.shift()
@@ -59,14 +63,14 @@ format = (fmt) ->
         when 'd'
           arg = Number(arg)
         when 'j'
-          arg = serialize arg
+          arg = serialize color, arg
       return arg if !escaped
       args.unshift arg
       match
     )
 
-  fmt += ' ' + serialize arg for arg in args if args.length
+  fmt += ' ' + serialize color, arg for arg in args if args.length
   fmt = fmt.replace(REGEX.escape, '%') if fmt.replace?
-  serialize fmt
+  serialize color, fmt
 
 module.exports = format