pretty sure its illegal. The light emitted from the fron of a vehicle MUST be white, yet for some reason yellow and HID (purpley green) are legal.
as long as the colour aint changed by tinging ur class then u may be ok. There exist some blue tinted headlights for corsa Bs and escort 6s and i think theyre legal,a tiny bit of smoking wont affect the light either.
Ive always wondered how iridescant headlights would look.