The light is indeed greenish, rather than the bright green of navigation lighting (https://www.conservationmagazine.org...t-green-light/
). My understanding is that it's not that the light is intended to be green, but that the red end of the spectrum is removed making it look more green to our eyes. Research has shown that it's the red component of lights that affect a birds ability to navigate, rather than them being attracted per se (e.g. https://www.nature.com/articles/364525a0
). I would imaging that there is some attraction going on, but the capture by light sources causing birds to fly around the light until exhausted, or they fly in to something, is apparently down to the red component of the light. Some island communities in the Netherlands have also installed these in street lighting to prevent bird "attraction".