Editing Metal-halide lamp (section)

==Color temperature==
[[Image:Metal Halide Lamp Spectrum.jpg|thumb|alt=Line graph of relative intensity vs wavelength| Output spectrum of a typical metal-halide lamp showing peaks at 385nm, 422nm, 497nm, 540nm, 564nm, 583nm (highest), 630nm, and 674nm.]]
Because of the whiter and more natural light generated, metal-halide lamps were initially preferred to the bluish mercury vapor lamps. With the introduction of specialized metal-halide mixtures, metal-halide lamps are now available with a [[Color temperature#Correlated color temperature|correlated color temperature]] from 3,000&nbsp;K to over 20,000&nbsp;K.  Color temperature can vary slightly from lamp to lamp, and this effect is noticeable in places where many lamps are used. Because the lamp's color characteristics tend to change during lamp's life, color is measured after the bulb has been burned for 100 hours (seasoned) according to [[ANSI]] standards. Pulse start metal halide lamps have improved color rendering and provided a more controlled kelvin variance (±100 to 200 kelvins) because of better arctube shapes compared to probe start metal halide lamp, which don't requires a starting electrode to be present and allow higher pressure and temperature of the halides.

The color temperature of a metal-halide lamp can also be affected by the electrical characteristics of the electrical system powering the bulb and manufacturing variances in the bulb itself. If a metal-halide bulb is underpowered, because of the lower [[operating temperature]], its light output will be bluish because of the evaporation of mercury alone.  This phenomenon can be seen during warmup, when the arc tube has not yet reached full operating temperature and the halides have not fully vaporized. It is also very apparent with dimming ballasts. The inverse is true for an overpowered bulb, but this condition can be hazardous, leading possibly to arc-tube explosion because of overheating and overpressure.