what does kelvin mean for lighting
Light color is measured on a temperature scale referred to as Kelvin (K). Lower Kelvin numbers mean the light appears more yellow; higher Kelvin numbers mean the light is whiter or bluer. Most ENERGY STAR certified bulbs are made to match the color of incandescent bulbs at 2200-3000K. For a whiter light, look for bulbs marked 3500-4100K. For bluer white light, look for bulbs marked 5000-6500K.