A lot of HID manufactures use a fairly arbirtary "color temperature" numbers, thus why there is disagreement on the viewable colors given at each color temperature. Color temperature is measured in (K) or Kelvin and is biased on an actual temperature of a black body radiator which radiates light at a specific hue, this hue, is the "color temperature" of a light source. Because the color temperature of 5500k correlates to the sun and the widest color band frequencies (a scale on which all spectrums of visible light are graphed), it is safe to say that the bulbs that most closely mimics that of the sun, is the brightest and easiest for our eyes to see since the band is fairly smooth without any harsh peaks. Somewhere between a warmer 5000k to a bit cooler 6000k is the "brightest" bulb although technically higher frequencies or warmer colors (red) are scientifically brighter. Therefore, although we may argue on which color temperature is "best", science says that the accurate color temperature of somewhere between 5000k and 6000k is your best bet albeit not the brightest.Originally Posted by matt5112
