Well HC, as I remember, that was exactly what it was for:
The CAA's attention was initially drawn to the issue of helideck status signalling systems as a result of concerns within the industry over 'wrong-rig' landings and their associated safety hazards. A study of offshore platform identification signs, reported in CAA Paper 92006 (Reference [2]), established that there was little prospect of resolving the problem through improvements to the signage and recommended the specification of a new visual aid, the helideck status signalling system.
I understand what you are saying though but had not thought (nor had others) of your unique solution. Would that work by Day?
Jim