While the colour is the main factor, the lux probably matters as well. Your article there specifically mentions eight lux, or twice the brightness of a night light. Would a faint light at four lux also have an affect? The articles don't seem clear.
I don't have a measurement handy for the lux on a kindle at the dimmest setting, nor can I find any details on if brighter lights have a more pronounced affect on melatonin suppression.
The thing is no matter what, this is still assuming that your preferred method of reading is the right one. Some people do not like the look of orange lights - personally I hate incandescents, and have been using CFLs and LEDs putting out white light for a long time now. Perhaps using said lighting directly inside the kindle looks particularly bad. Perhaps they assumed people want to stay awake while reading.
Making a design decision you don't agree with means they made a design decision you don't agree with - not that they don't care or are incompetent.
I don't have a measurement handy for the lux on a kindle at the dimmest setting, nor can I find any details on if brighter lights have a more pronounced affect on melatonin suppression.
The thing is no matter what, this is still assuming that your preferred method of reading is the right one. Some people do not like the look of orange lights - personally I hate incandescents, and have been using CFLs and LEDs putting out white light for a long time now. Perhaps using said lighting directly inside the kindle looks particularly bad. Perhaps they assumed people want to stay awake while reading.
Making a design decision you don't agree with means they made a design decision you don't agree with - not that they don't care or are incompetent.