As nouns the difference between farb and darb
is that
farb is (us) a historical reenactor (especially a us civil war reenactor) whose efforts at a historically accurate portrayal are, in the opinion of the speaker, inadequate (for example, wearing a modern wristwatch with period costume) the opposite of
farb is "hard-core" (or hardcore), someone who is, in the opinion of the speaker, an "authenticity fanatic" while
darb is (australia|slang) a cigarette.