Copper hair dye is a type of hair color that is used to add red or orange tones to the hair. It can be used to create a natural-looking redhead or to add highlights to brown or blonde hair. Copper hair dye is available in both semi-permanent and permanent formulations, and can be applied at home or by a professional stylist. It is important to note that the color of the dye may vary depending on the brand and the underlying color of the hair, and a patch test is recommended before applying the dye to the entire head of hair.