Over the years, fluorescent bulb manufacturers had some challenges getting users to accept the white color produced by fluorescent technology. Because of the limitations of phosphor technology, the fluorescent industry introduced subjective terms such as "cool white" or "warm white" to draw comparisons to incandescent white. Not coincidentally, white LED ljusskyltar manufacturers face the same challenges since white LED technology is based on phosphor energy. To put things in quantitative perspective, LED manufactures have referred to Color Rendering Index (CRI) which is a measurement of a light source's ability to render colors accurately. The higher the CRI, the more natural the colors appear, with natural sunlight having a CRI of 100. However, this may not be the best metric for comparing light sources. Originally developed in 1964, this index is based on color models with broad spectral distributions. White LEDs ljusskyltar are narrow-band sources. Color Temperature may be a more suitable tool for comparison because it is a less subjective measure, based on degrees Kelvin. Presently there are several white emitters to choose from in the 3,200 degree-Kelvin and 5,500 degree-Kelving range. No matter how the color is measured, LED ljusskyltar manufactures have made great strides to match the warm white glow of an incandescent bulb with high-quality LEDs due to the tremendous demand for incandescent white tones.