John Kitchin <jkitchin@andrew.cmu.edu> writes:

> I have this set:
>
> (setq org-src-fontify-natively t)
>
> but the code blocks are all black text.
>
> Is there a known issue with a transition from 8.2.10 to 8.3 that would
> affect fontification? or some previous setting that would interfere with
> it? Thanks,

Are you using a developmental build of Emacs?  If so, it should be fixed
if you update your build.

Here are the details from Org's eb3b104 (org-src: Use font-lock-ensure
to highlight blocks, 2016-01-29):

    * lisp/org-src.el (org-src-font-lock-fontify-block): Use
      org-font-lock-ensure instead of font-lock-fontify-buffer.

    This replacement has previously been made (f36b19e, d81e6b5) and then reverted
    (99f9999, 003a0f1) twice because source blocks were not being reliably
    highlighted when font-lock-ensure was used instead of
    font-lock-fontify-buffer.  This was due to a bug in font-lock-ensure
    that has now been fixed (see Emacs's 21beb19 and bug#22399).

    font-lock-ensure was introduced after Emacs 24.5, so this issue only
    pertains to users with a developmental version of Emacs.

--
Kyle