Although newer versions of Ubuntu (10.04 and up) already come with the helpful nano syntax highlighting enabled, older versions don’t – though thankfully switching this on is pretty simple to achieve.
To enable nano syntax highlighting for a user, first copy the nanorc file to the users home directory:
cp /etc/nanorc ~/.nanorc
Next, edit the file, scrolling down to the bottom of the file and uncommenting the lines for the languages you wish to turn syntax highlighting on for.
Save your changes and fire up nano against a file with a recognised language extension to see the colorful result.
Easy peasy :)