In org-mode, a line starting with a colon is formatted as source code. ( http://orgmode.org/manual/Literal-examples.html )
In literate Haskell, source code lines start w
Not an exact answer to your question, but an example of how I write literate Haskell using org: https://github.com/haroldcarr/make-mp3-copies
The README.org is the literate Haskell, the MakeMP3Copies.hs is the resulting haskell file that is "tangled" out of the .org file.
I export to HTML and publish on my blog: http://haroldcarr.com/posts/2013-09-11-flac-to-mp3-via-haskell-shelly-and-ffmpeg.html
The README.org also autorenders on github (although there is some stuff in the autorendering that is only meant for HTML that I have not taken the time to fix).