I dunno man, cause what I heard is they are supposed to REFLECT red light, but you could argue that your third brake light does that. A friend of mine had clear tails on his 89 civic hatch, and after being pulled over approx 13 times (I am not exagerating) he painted the corner part of em red.
Most places have stopped carrying clear taillights because their legality is questionable, the main reason they became illegal is because a bunch of idiots didnt put in red bulbs.
I know I can get a set of clear tails for my 91 sedan for $170 over on autodynamic.com, but I dont want to spend money on it if its illegal, and I kinda like my stock tails. What I am currently thinking of doing (since they dont make altezzas for the sedan) is trying to get a clear centerpiece, and then paint the actual tails all red, so I would have a big red clear, but I dunno.