I just learned a nice trick from the Org Mode Mailing List. By default code blocks in Org-mode buffers are colored gray and don’t show the fontification the way it does in a normal programming buffer. But if you add
(setq org-src-fontify-natively t)
to your .emacs or init.el file you get normal fontification for whatever language you’re using. This is especially nice when you open an editing buffer with【Ctrl+c '】 to insert code into the #+begin_src ... #+end_src area.