If you have trouble getting restful sleep at night, changing your bed side reading light might be a bright idea.
Recent research suggests that an increase in the blue wavelengths of light at night can cause a decrease in melatonin levels, the hormones that influence sleep rhythms.
Harvard researchers and their colleagues conducted an experiment that compared the effects of 6.5 hours of exposure to blue light with that of green light. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much.
In-short the study found all light night can negatively influence melatonin production but bulbs with a blue color temperature are especially damaging to sleep.
Light bulb manufacturers offer higher energy efficiency light bulbs that typically produce white light more on the blue side of the spectrum but finding a warmer color is pretty simple when you know what to look for. Try to find light bulbs with a lower K (Kelvin) rating. Bulbs with a lower Kelvin rating will have a warmer more reddish tone which may be more appropriate for a bed side table lamp or night light.