For questions about the syntax highlighting performed inside code blocks on Stack Exchange sites.
Stack Exchange uses Prettify, a JavaScript library, for syntax highlighting of code blocks across the network.
Improvements to the highlighting for any specific language are most readily obtained by submitting patches to Prettify's GitHub project, then (once the patches are accepted) requesting that Stack Exchange update to a revision of Prettify that includes them.
Improvements to the way Stack Exchange sites integrate Prettify should be requested here on Meta Stack Exchange and given the tags prettify and (feature-request or bug).
For information on available languages and how to use syntax highlighting, see What is syntax highlighting and how does it work?.
