Philips says that herring gulls, common terns, and other migratory birds are less likely to lose their way with blue-green lighting in place, such as here on Ameland, where Philips expects to complete the installation by later this year.
Cyan? (looks like)
I doubt those birds would get lost without them though.
Now why does that make me think the costs are probably totally outrageous? 
I remember once Texas_Ace asked himself to whom the greenish tinted portion of LEDs sold. This might be one of the project.
The picture is beautifully unreal
- Clemence
Judging by the picture, the light looks monochromatic, not just green (cyan) tinted.
I have some cyan LEDs here, put one in a SF348 (just for fun).
Funny thing is that certain colored objects are fluorescent under cyan light, and give off green, yellow or orange reflection.
LED phosphors for example.
Blue pump LED, UV pump LED, purple pump LED, now there’s a possibility for cyan pump LED