NOT THAT LONG AGO, when your 60-watt incandescents burned out, you simply bought another box of the same. But incandescents were phased out beginning in 2012. Now the bulbs du jour are energy-saving LEDs, which produce light color that ranges from warm yellow to cool blue-white. LEDs trim your electric bill, and many manufacturers claim their bulbs last 10,000 to 50,000 hours. If the bulb is used for 3 hours a day, that’s about nine to 46 years! But choosing the right bulb for your room is a little more complicated. Here, a primer to light your path to an easy decision.