Many choices exist for efficient lighting that provide light that is similar to traditional incandescent lighting in terms of color rendering while using less energy, producing less heat, and potentially providing a longer life than incandescent bulbs. The most common types of high-efficiency lighting are compact fluorescent lamps (CFLs), pin-based fluorescent tubes, and light emitting diodes (LEDs).
Most energy efficient lighting products come in "warm" colors to match the yellowish light of incandescent bulbs but can also come in "cooler" colors that provide whiter or bluer light. The wide variety of shades of white light, ranging from yellowish to white to bluish white light allows one to customize the mood of any space. Light color is measured on a temperature scale referred to as Kelvin (K). Lower Kelvin numbers mean the light appears more yellow while higher Kelvin numbers mean the light is whiter or bluer. For example:
- For a warmer light, look for bulbs marked 2700-3000K
- For a whiter light, look for bulbs marked 3500-4100K
- For bluer white light, look for bulbs marked 5000-6500K