I haven't tought about it, but now that you mentioned it seems obvious.
It's more of a background color, when I for example watch tv in another part of that room. It gives an ambient so I see shapes of furnitures but it doesn't attract attiention. Also it's subtle dark blue, nothing like the one that shines brightly from your phone straight into your eyes (I think it matters). I also never have problems falling asleep, since I get up early, I fall asleep in a matter of few minutes around 10-11pm.
Correct, our eyes have cells that respond to certain wavelengths ("blue light") and send signals through nerves to the brain, but those nerves aren't attached to the visual cortex, they are attached elsewhere. And that's why "blue light" inhibits sleep. ...I wish I could provide a citation, these details are something I just heard late last week...