Take a look at this post for instance - the C# good examples are outlined perfectly, however the Java ones are poor. I am while using latest version of WP-Syntax

BTW, performs this belong on UserVoice or here? I could not quite decide.

I checked the CSS also it appears that styles are inlined. And So I believe that the Java config of Wordpress-Syntax is applying these ugly defaults. If Wordpress-Syntax was using CSS courses of instruction for the highlight, it might be easy to fix.