Under the hood, the plugin used to highlight the code is Rainbow, by Craig Campbell.
Unpack and upload it to the /wp-content/plugins/ directory.
Activate the plugin through the 'Plugins' menu in WordPress.
Here are some key features of "WP Colored Coding":
· Supports themes
· Multiple code blocks on the same page
· Code blocks are kept separate from the post
· Code blocks are separately kept in the database
· WordPress 3.3 or higher
What's New in This Release: [ read full changelog ]
· Spanish language files.
· Rainbow support for Go, R, Coffeescript, Java, Smalltalk.