 In the absence of a reference, this mixture appears white to the eye, but the light has an incomplete spectrum.The color rendering index (CRI) of such lamps is around 60.Since the 1990s, higher-quality fluorescent lamps use either a higher-CRI halophosphate coating, or a "triphosphor" mixture, based on europium and terbium ions, which have emission bands more evenly distributed over the spectrum of visible light.