Only the red lights are LEDs, parking and brake. The turn signal and reverse lights are regular bulbs. The LEDs cannot be replaced, I recall the manual stating that if 2 or more LEDs go out, the tail lights will need replacing to meet vehicle code.
I've heard there is a minimum size taillights have to, something like an "x" number of square inches. This I can't confirm as I heard from the person a way for cops to cite people with those cheesy wanna be Altezza lights on their Civics and such.