Cool How Long Does Unopened Hair Dye Last References. Web yep, hair color, like nearly every other cosmetic product on the market, eventually expires. Web l’oréal paris says that their l’oréal preference hair dyes will expire after 3 years.
As hair dye stays on your shelf for longer, the quality and effectivity of the color decrease. Proper storage in this case refers to the climate the dye is kept in. Web cosmetic products, including hair dye, usually include two types of expiration dates:
