Quote from: M2018 on December 19, 2019, 12:54:03
@ S.Yu
Standard daylight is about 5200K, not 6500.

Well there are certainly different theories about this.
http://www.bobatkins.com/photography/tutorials/white_balance/color_temperature(2).jpg

Biological clock from human is made to keep the up during the day, therefore they will be fully awake when it's midday (blue light) and less awake during the evening and morning (yellow light).

Biological clock from mice aren't the same, mice are more active than human during the night... I really don't see the point to do a study on a mice for that as there is a big difference. I'm sure that a study on bat or owl will suggest that they are more sleepy with blue light...

I don't think it's the case of just setting the white balance for "night mode". And even if it matters, switching just to arbitrarily chosen value won't help much - while, yeah, daylight WB varies between 5000-5600K, overcast sky and default white balance in most displays we use is at 6500K - so if you're "nightmoding", you'd have to go for values closer to 2000-2500K or even lower (warm, incandescent bulb or candlelight).
But there's an issue here - it may be tough to read text. It means you'll be actively working on deciphering words and you won't fall asleep so easily.
So to counter that, maybe brightness will be upped a bit and you'll effectively start mimicking daylight brightness (especially since it's not an ambient light, but targeted directly towards your face, at close distance)
Then, since it's often close distance, and it's basically reddish hue that's blasting at your retinas(even lowest brightness settings at night are really bright), it may result in cortisol pumping through your veins (cortisol level is at highest level when you wake up and slowly goes down during the day - the lower level, the "relaxed/sleepy" you should be; it should hit the lowest at midnight+-2 hours).
While blue light also lowers melatonin level (high level means "sleepy", low means "awake", in simplified terms), the heightened cortisol level resulting from reddish "night mode" may make going asleep harder.
Only solution is unfortunately going dark, preferably at least half an hour before getting to bed - or at least switching to warm ambient(not targeted directly at our eyes) light and grabbing a book.

@ S.Yu
Standard daylight is about 5200K, not 6500.

Well, mice are nocturnal, so I'm extremely skeptical about how you could apply the findings of such a study to humans. The morning blue light which signals us to awaken is the signal for mice to sleep

Well... Orange street lights are annoying when you're trying to sleep. I have to shut them out completely to be able to sleep normally.
On the other hand, the "night mode"/"blue light reduction mode" on my tablet works very well for me. If I turn it up all the way, I start to feel more sleepy/less awake and usually fall asleep easily after putting away the tablet.
So I think the study is wrong. Why'd you test something like that on mice anyway? Just use real people with their real phones for the study, then maybe you will get real results. >__>
Seriously, you'd think scientists would have more brains than that.

Well, the standard daylight WB is 6500K, which is quite blue, while dawn and dusk have lower color temperature.