Starting in 2012, information labels similar to the one shown will be required on all bulb packaging, so we'll know exactly what we're buying. If you want a bulb that's as bright as a 60-watt incandescent, look for a brightness of 700 to 850 lumens; the higher the lumen count, the brighter the bulb. Light appearance (or color temperature), measured in kelvin, indicates how warm or yellowish the light is. Look for a number around 2,700 kelvin, roughly equal to that of an incandescent. (As a comparison, candlelight measures around 1,700 kelvin, and daylight, 6,500 kelvin.) A third figure, not on the label but often listed on the bulb maker's website, is the color rendering index (CRI). It ranges from 0 to 100 and measures how well a light illuminates colors. While incandescents rank close to a perfect 100, any bulb with a CRI of 80 to 90 suits all but the most discerning eyes and will let you see colors accurately.
As of January 1, 2012, a modified version of this label will be required on all bulb packaging to help consumers make informed choices.