To fart while holding a lit lighter a few inches from ones butt-hole. "You should have been there last night, when Jonny lit up a blue flame and burned his asshole"
A derogative term that borrows from both the concept of the "blue-platespecial" and the practice of "blue flaming" to suggest a generic knucklehead, most likely male.
Son, you're a regular blue flamespecial- young, dumb and full of cum.