If you listen to or read paleo related podcasts or blogs then you have probably heard about the effects blue and red light have on our natural Circadian rhythms.
Actually you may have heard references to this subject outside of the paleo world also. The suggestion to stop backlight devices before bed for better sleep comes from this idea.
Basically, blue light mimics the effect of sunlight on our brains, making them think it is still day time well after sunset increasing serotonin secretion and impeding our ability to fall and stay asleep.
On the other hand red light can mimic dusk and sunset times of day allowing our bodies to naturally go through their hormonal secretions in preparation for sleep (melatonin)
What I did is replaced all but two lamps (one beside the bed and one in the living room) with blue spectrum light bulbs (usually called « daylight bulbs »).
The lights with the blue light bulbs are turned on when we get up in the morning (5am most months is before sunrise) then after sunset (when we are done our days) we turn on the red lights.
It is amazing the changes this has made in my life. Waking in the morning is a lot easier even through the winter months and winding down at night is a much smoother process.