diff --git a/lib/awesome_print/formatter.rb b/lib/awesome_print/formatter.rb
index a639168..98fb6df 100755
--- a/lib/awesome_print/formatter.rb
+++ b/lib/awesome_print/formatter.rb
@@ -39,12 +39,19 @@ module AwesomePrint
 
     # Pick the color and apply it to the given string as necessary.
     #------------------------------------------------------------------------------
-    def colorize(s, type)
-      s = CGI.escapeHTML(s) if @options[:html]
+    def colorize(str, type)
+      str = CGI.escapeHTML(str) if @options[:html]
       if @options[:plain] || !@options[:color][type] || !@inspector.colorize?
-        s
+        str
+      #
+      # Check if the string color method is defined by awesome_print and accepts
+      # html parameter or it has been overriden by some gem such as colorize.
+      #
+      elsif str.method(@options[:color][type]).arity == -1 # Accepts html parameter.
+        str.send(@options[:color][type], @options[:html])
       else
-        s.send(@options[:color][type], @options[:html])
+        str = %Q|<kbd style="color:#{@options[:color][type]}">#{str}</kbd>| if @options[:html]
+        str.send(@options[:color][type])
       end
     end
 
diff --git a/spec/misc_specs.rb b/spec/misc_specs.rb
index 3cc6942..f438276 100644
--- a/spec/misc_specs.rb
+++ b/spec/misc_specs.rb
@@ -101,5 +101,43 @@ EOS
 }
 EOS
     end
+
+    describe "Coexistence with the colorize gem" do
+      before do # Redefine String#red just like colorize gem does it.
+        @awesome_method = "".method(:red)
+        String.instance_eval do
+          define_method :red do   # Method arity is 0.
+            "[red]#{self}[/red]"
+          end
+        end
+      end
+
+      after do # Restore String#red method.
+        awesome_method = @awesome_method
+        String.instance_eval do
+          define_method :red, awesome_method
+        end
+      end
+
+      it "shoud not raise ArgumentError when formatting HTML" do
+        out = "hello".ai(:color => { :string => :red }, :html => true)
+        out.should == %Q|<pre>[red]<kbd style="color:red">&quot;hello&quot;</kbd>[/red]</pre>|
+      end
+
+      it "shoud not raise ArgumentError when formatting HTML (shade color)" do
+        out = "hello".ai(:color => { :string => :redish }, :html => true)
+        out.should == %Q|<pre><kbd style="color:darkred">&quot;hello&quot;</kbd></pre>|
+      end
+
+      it "shoud not raise ArgumentError when formatting non-HTML" do
+        out = "hello".ai(:color => { :string => :red }, :html => false)
+        out.should == %Q|[red]"hello"[/red]|
+      end
+
+      it "shoud not raise ArgumentError when formatting non-HTML (shade color)" do
+        out = "hello".ai(:color => { :string => :redish }, :html => false)
+        out.should == %Q|\e[0;31m"hello"\e[0m|
+      end
+    end
   end
 end