Hi,
I decided to add this info to this 3 month old post as it's the most logical place.
I found this reputable information about the fact that backlit devices block (or slow) the increase of melatonin at night (the chemical substance the body manufactures to help you go to sleep) - see this link:
http://www.nature.com/scitable/blog/...s_you_awake_at
Hence e-ink ereaders, paper books, yellow glasses or non-blue backgrounds on your device won't interfere as much with your ability to go to sleep.
Paul