b'Color temperature.Color temperature is measured in Kelvins and LUM specifies a 4000K color temperature for clean neutral white illumination.1000K 2000K 3000K 4000K 5000K 6000K 7000KWARMLUM COOLDAYLIGHTWHITE NEUTRAL WHITE WHITEColor Rendering Index (CRI) An international numbering system used to rate a lamps ability to render an objects color. The higher the CRI (based upon a 0-100 scale) the richer and truer the colors.CRI 97 CRI 90CRI 80 CRI 70LUM LIGHTING | 069'