Here in the Netherlands the use of green light (540nm) is becomming popular for night lights. It doesn't disrupt sleep patterns of humans, animals and plants and your eyes can see quite well using less brighter lights (saves energy). And green LEDs are relatively cheap.
In studies both green and blue light showed to be the least disruptive (but green is better for night sight). I thought this was strange since it was always believed that blue light is bad.
But it appears this article agrees.
Edit: a lot of plants and corals are grown under red light. So maybe red could be more harmful for your sleep if it triggers growth.
Plants need both blue and red light to grow. Also, plants and animals are so fundamentally different biologically that very few things which affect one have any direct reason to have similar effects on the other.
In studies both green and blue light showed to be the least disruptive (but green is better for night sight). I thought this was strange since it was always believed that blue light is bad.
But it appears this article agrees.
Edit: a lot of plants and corals are grown under red light. So maybe red could be more harmful for your sleep if it triggers growth.