I think a note at the top: "this story is meant to be read in its original plumage!" would help at least alert me to what was going on. A link to the preferred form for reading would be helpful too, but my RSS reader should be able to generate such a thing if I ask nicely.

"Colloquial" just doesn't sound right to me for describing an actual tone of voice. It seems more like it would describe word choice. Perhaps "casually" would make me happier, but ultimately they're your words.

Ethan