see here for more details on the requirement for green helideck lights:
http://www.hse.gov.uk/foi/internalop.../spctosd29.pdf
Green perimeter lighst will be mandatory, but I'm not sure if it's by the start or end of 2008 (Stage 1).
There will also be a further requirement to have an illuminated 'H' (Stage 2). As far as I'm aware no vendor has approved lighst available (yet) to meet this requirement.