Color Temperature
Color temperature is conventionally stated as Kelvin temperature, having the unit symbol K. Color temperatures over 5,000K are called cool colors (bluish white), while lower color temperatures (2,700–3,000K) are called warm colors (yellowish white through red).
Offices would typically use 4000K, while a warehouse or manufacturing plant is better served with brighter, 5000K (whiter white).
Foot Candles
The unit of measurement indicating how much light is reaching the surface, 30 inches above the floor.
CRI
Color rendering index is the color appearance of an object when illuminated. Scales ranges from 0 to 100. The higher the CRI number, the less distortion of the object’s color, providing a more accurate rendering of the objects actual color. Today’s LED fixtures have a much better color rendering ability.