LED Facts Card - Learning Objectives
Why did the DOE (Department of Energy) create and mandate that the 'Lighting Facts' data to be printed on packaging for light bulbs?
Since LED light sources do not mimic daylight, there is a need to have some metrics for comparison to familiar light sources of sunlight, incandescent and halogen. Lighting Facts is a good start, for more details consider the Kelvin, CRI, and TM-30 metrics.
LED = Light Emitting Diodes - now the standard for new construction in the state of California, mandated by Title 24 energy code power limits, the most restrictive power allowances in the world, preceding adoption of similar codes worldwide. LED bulbs (or lamps as the lighting industry calls them, or Light Engines as the lighting designers call them) are inherently color biased. Since the Blue White chip was developed for the commercial market, manufactures have been struggling with achieving balanced white light. A combination of coatings, voltage, age, and manufacturing processes all affect an LED's spectral and lumen output, industry terms for color and brightness.
Good lighting design should always include analysis of color rendering, light intensity, beam spread, flicker, and glare.
GLARE = Visual Disability Due to the extremely small light source of LEDs, glare can cause visual disability - squinting and averting the eyes.
EYE ADAPTATION = Increases with age and brightness. LEDs can be too bright. "There's well over a million-fold change in intensity between a starlit night and a bright sunny day at the beach. This is a challenge for the nervous system because neurons have a very limited response range: -80mV to +50 mV of graded potential in the non-spiking cells of the retina, or 0 to about 200 spikes per second for ganglion cells. The retina solves this problem by adapting to the ambient level of illumination. If the light level changes by a relatively small amount, then the visual system compensates for the change almost immediately. However; if the light level changes by a lot, then the eye takes a long time to re-adjust." 
Light Source Choices = The bewildering array of light bulb choices is confusing. Industry professionals refer to light bulbs and light sources as 'lamps'. Examples of how colors appear under different light sources are discussed on this page. As LED lamps continue to evolve, there are many decisions to be made about color rendering (ability of light source to show color of objects and surfaces) and light output (intensity of light emitted measured in lumens).
R9 Color Rendering Test Colors
Color Rendering Index (CRI) indicates the ability of a light source to render color accurately. The problem is that the original 8 muddy colors, and the addition of 4 additonal colors are not enough to judge a light source's ability to accurately render all colors.
Sunlight and Halogen Incandescent lighting score 100 serving as the basis for color comparisons for values of CRI.
Regulations in California (Title 24) require 90 CRI or higher in Residential applications. Commercial projects often use light sources with 80 CRI or as low as 70.
As LED light source technology advances, the CRI is improving; however, it is important to learn about the color rendering and limitations of a particular light source before specifying or purchasing, since most light sources cannot be returned, because the wholesaler or retailer cannot tell how many hours the lamp (light source) has been used.
TM-30 Color Type Key:
A-Nature B-Skin C-Textiles D-Paints E-Plastics F-Printed Materials G-Color Systems
TM-30 Color Rendering Test Colors
Lighting Facts - Comparing the numbers
DOE - Department of Energy