I think the clear tail lights look better on a light coloured body like white or silver than a dark coloured body.Originally posted by Altezza:
Currently as a dealer option in Japan, there is a taillight cover that goes over the chrome part of the taillights. This comes in all body colors, but is just added on outside the outer covers, so it doesn't look so good.
But I guess the one you're talking about is taillights with clear covers with body color inside instead of the chrome it currently has. Well, this kind of taillight is not on the dealer option as of now, but some backyard parts manufacturers have been making them (in Japan). But the rumor is that from next year's model, IS will have body color taillights except silver and white. When that comes out, it will be possible to order the new taillights as supply parts (usually ordered for repairs) and replace your current taillights.
It may cost a lot though. Probably around US$400 a piece (US$800 a pair). Its just a wild guess though.