rear lights on Elise S1

[sdw2003]

I own an Elise S1 Titanium and am looking to replacing all the inidcator lenses with the smoked versions.

I was wondering, what is the legal requirements on the rear light (red) lenses? Could these be replaced with smoked lenses, and if so does anyone know a company that sell red bulbs, in a similar way you can get yellow bulbs for the indicators.

Thanks in advance of any help/advice

Scott.