ABSTRACT
Some manufacturers improved the color rendering of color mixing Light-emitting diode (LED) luminaires by adding an amber LED or, in some cases, several other colors, including red, red-orange, amber, green, lime, cyan, blue, and indigo. There has been rapid and steady improvement in LED technology and in metal halide lamp sources, which has led to the almost total abandonment of tungsten light sources in new stage lighting. When LEDs came into prominence in the lighting industry it was soon realized that color rendering index was inadequate for measuring color fidelity, especially when a lighting instrument uses red, green, and blue LEDs to produce white and colored light. The arc produces a series of wavelengths in the visible spectrum that, taken as a whole, are perceived as white light. The arc lamps most commonly used in automated lighting have a correlated color temperature of about 5600K or higher.
