Green Electric LED Lighting can have a powerful impact in our environment
Key aspects of lighting quality are color appearance and color rendering, both of which are explained below:
Color appearance is communicated using correlated color temperature (CCT) on the Kelvin (K) scale. For most interior lighting applications, warm-white (2700K to 3000K) and in some cases neutral-white (3500K to 4000K) light is appropriate. Cool-white (6500k) LEDs with very high CCT (bluish in appearance) tend to offer higher efficacy at low cost, but may not meet user expectations for color. An increasing number of high-efficacy LED products are available in warm-white or neutral-white colors, to the point where many have surpassed CFLs. Two light sources with identical CCTs can render object colors very differently due to the differences in spectra. While CCT provides an indication of whether a light source may appear yellowish or bluish in color, Duv is an additional metric that can help identify sources with excessively greenish or pinkish hues.
Color rendering, or color rendering index (CRI) measures the ability of light sources to render colors, compared to either incandescent reference sources if warm in color, or daylight reference sources if cooler in color. The leading high-efficiency LED manufacturers now claim a CRI of 80 or higher for phosphor-converted, warm-white devices. In general, a minimum CRI of 80 is recommended for interior lighting, with CRIs of 90 or higher indicating excellent color rendering.