Very interesting article. I've known for a long while our eyes were most receptive to green light, up until now I never it was our peak sensitivity to light is at 555nm aka green
I've had to do the same thing for my iOS enterprise app. The issue is that you can't play audio if you're app is in the background and you haven't used your audio session in the past 1-2 minutes.
The workaround is to play a silent audio mp3 to prevent the app's audio session from being suspended.
The proper fix would be for apps to be allowed to start audio from the background