Site name with html tag
Its not at all difficult. I tried it in Drupal 7.22

Goto Configuration => Site Information => Site Name => 

My Site &lt;span class="dummy-class"&gt;This is my new website&lt;/span&gt;


Add whatever tags you like to have. But remember site title itself is already inside &lt;span&gt; tag, which means you have some restriction (Span tag is not container).

This is what it looks when I inspect it using firebug in mozilla.


In your case, its Good&lt;span&gt;4&lt;/span&gt;You. Just by using css you can do the magic.