This is one reason why I use a European model Samsung Galaxy S3 (GT-I9300) for ebooks. It includes "mDNIe" which gives you very flexible OLED display configuration on rooted phones. You can completely turn off the blue channel and remap blue to green so blue things remain visible. I use the "Galactic Night" app for switching between mDNIe modes.
To further reduce light exposure I use gray (remapped to yellow) text on a black background (very dark because the display is OLED). I set the screen brightness to maximum in FBReader to avoid PWM flicker, and reduce the text brightness to compensate. I also disable the phone indicator LEDs. I don't find reading like this to harm my sleep.
The one problem is that the mDNIe mode very briefly flashes to default when the phone is first turned on from standby. I think this could be fixed with a kernel patch but I just avoid looking at the screen then.
To further reduce light exposure I use gray (remapped to yellow) text on a black background (very dark because the display is OLED). I set the screen brightness to maximum in FBReader to avoid PWM flicker, and reduce the text brightness to compensate. I also disable the phone indicator LEDs. I don't find reading like this to harm my sleep.
The one problem is that the mDNIe mode very briefly flashes to default when the phone is first turned on from standby. I think this could be fixed with a kernel patch but I just avoid looking at the screen then.