you can order headlight covers from your Lexus dealer
However, you need to be aware that you need to remove your front bumper, before you can remove your old head lights and install the new head lights.
I have heard that there are greenish headlights, but only have sold the black chrome headlights.
Personally, I think that there are other mods more valuable, like replacing the old-style taillights for the new ones, replacing the dash bezel with the new one with the chrome rings, ...
I have the chrome ones, but you really need to look twice (or park it next to a GS with the old head lights) before you can see it.