Color, Temperature

the color of the luminescence from a heated metal alloy, which is determined by the metal’s temperature. Some typical temperature colors for steel are dark brown (550°C), dark red (680°C), cherry red (770°C), bright red (900°C), yellow (1000°C), and white (1300°C). Temperature colors may vary slightly with illumination. Before the advent of pyrometers and suitable testing and measuring instruments, the temperature of heated metal was determined from the temperature color.