A lot of people are borderline incapable of waking up in the dark and functioning normally throughout the day. There are a lot of physiological triggers sunlight exposure in the morning does to naturally wake most people up, and deviating from those can be quite unhealthy.
Artificial lighting, white not yellow, and lots of it, can help with that.
Anecdotally, when I moved my clothes into the guest room and got ready for the day with all the lights on instead of getting dressed by nightlight, I was much more wakeful. Also made fewer errors with navy/black socks :)
In Australia, Philips sell an LED bulb call SceneSwitch[1] (formerly Choose Scenes), which alternate between cool and warm white when switched off and back on. I've installed in all but the bedrooms.
