The color temperature of a light, measured in kelvins, is its most noticeable characteristic. A candle, at 1900 K, appears orange. Daylight, at 5500 K, is much whiter and bluer. A 5500-K bulb, however ...

GE traces its roots back to Thomas Edison, the inventor of the first practical, long-lasting light bulb in 1879. One hundred and forty years later, his company appears to be having trouble ...