Editing Compact fluorescent lamp (section)

===Spectrum of light===
[[File:Simple spectroscope.jpg|thumb|188px|right|Emitted visible light spectrum of an incandescent lamp (mid) and a CFL (bottom)]]
[[File:Spectral Power Distributions.png|thumb|Characteristic spectral power distributions (SPDs) for an incandescent lamp (left) and a CFL (right). The horizontal axes are in [[nanometer]]s and the vertical axes show relative intensity in arbitrary units. Significant peaks of UV light are present for CFL even if not visible.]]
[[File:CFBulbs.jpg|thumb|upright|A photograph of various lamps illustrates the effect of color temperature differences. From left to right:<br />{{•}} Compact Fluorescent (General Electric, 13&nbsp;W, 6500&nbsp;K)<br />{{•}} Incandescent (Sylvania, 60&nbsp;W, Extra Soft White)<br />{{•}} Compact Fluorescent (Bright Effects, 15&nbsp;W, 2644&nbsp;K<br />{{•}} Compact Fluorescent (Sylvania, 14&nbsp;W, 3000&nbsp;K)]]
CFLs emit light from a mix of [[phosphor]]s, each emitting one band of color with some bands still in the [[ultraviolet]] range as can be seen on the light spectrum. Modern [[fluorescent lamp#Phosphor composition|phosphor designs]] balance the emitted light color, energy efficiency, and cost. Every extra phosphor added to the coating mix improves color rendering but decreases efficiency and increases cost. Good quality consumer CFLs use three or four phosphors to achieve a "white" light with a [[color rendering index]] (CRI) of about 80, where the maximum 100 represents the appearance of colors under daylight or other sources of [[black-body radiation]] such as an [[incandescent light bulb]] (depending on the [[correlated color temperature]]).

[[Color temperature]] can be indicated in [[kelvin]]s or [[mired]]s (1 million divided by the color temperature in kelvins). The color temperature of a light source is the temperature of a [[black body]] that has the same [[chromaticity]] (i.e. color) as the light source. A notional temperature, the [[correlated color temperature]], the temperature of a black body that emits light of a hue that to human color perception most closely matches the light from the lamp, is assigned.

The color temperature is characteristic of black-body radiation; practical white light sources approximate the radiation of a black body at a given temperature, but will not have an identical spectrum. In particular, narrow bands of shorter-wavelength radiation are usually present even for lamps of low color temperature ("warm" light).<ref>[http://www.palagems.com/gem_lighting2.htm Buying and Selling Gems:What Light is Best? Part II: Artificial Light – The Options Available] See figures 6 and 7</ref>

As color temperature increases, the shading of the white light changes from red to yellow to white to blue. Color names used for modern CFLs and other tri-phosphor lamps vary between manufacturers, unlike the standardized names used with older halophosphate fluorescent lamps. For example, Sylvania's Daylight CFLs have a color temperature of 3500&nbsp;K, while most other lamps called ''daylight'' have color temperatures of at least 5000&nbsp;K. In United States, [[Energy Star]]'s specification provides a set of named color temperatures for certified luminaries.

{| class="wikitable"
|+Energy Star color temperatures<ref>{{cite web|title=Energy Star Program Requirements Product Specification for Luminaires 2.0|url=https://www.energystar.gov/sites/default/files/Luminaires%20V2%200%20Final_0.pdf|access-date=4 June 2017}}</ref>{{rp|26}}
|-
! rowspan=2 | Name
! colspan=2 | Color temperature
|-
! ([[Kelvin|K]])
! ([[Mired]])
|-
| Soft white ||style="background-color:#{{Color temperature|2700|hexval}}"| 2700 || 370
|-
| Warm white ||style="background-color:#{{Color temperature|3000|hexval}}"|  3000 || 333
|-
| Neutral White ||style="background-color:#{{Color temperature|3500|hexval}}"|  3500 || 286
|-
| Cool white
| style="background-color:#{{Color temperature|4050|hexval}}"|4000&mdash;4100
| 250&mdash;243
|-
| Daylight
| style="background-color:#{{Color temperature|5750|hexval}}"|5000&mdash;6500
| 200&mdash;154
|}