While synthetic hair cannot be dyed using conventional hair-dyeing techniques, synthetic hair dyeing kits exist, and it is possible to dye synthetic hair using a dye that will adhere to plastic and will not rinse off with water. It is much harder to dye synthetic hair because fewer coloring techniques will adhere to plastic than to hair.
Synthetic hair is typically made of nylon or different types of plastics. Dyeing these materials takes heavy-duty coloring because nylon and plastic are slick materials, and most dyes wash right off. When attempting to color synthetic hair, it is important to choose a darker color than the color of the hair because if the hair is dyed a lighter color, the darker hair underneath will show through.